SUMMARY
Trying to restart the computer while in a session causes only the session to end and returned to the login screen.


STEPS TO REPRODUCE
1. Application Launcher
2. Leave
3. Restart

OBSERVED RESULT
Returned to the SDDM login screen where I have to press the restart button there.

EXPECTED RESULT
Computer restarts


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Archlinux 
(available in About System)
KDE Plasma Version: 5.19.1
KDE Frameworks Version: 5.71.0
Qt Version: 5.15.0

ADDITIONAL INFORMATION
There was also a crash during logout by kglobalaccel5, but I'll post that in there.
It's been like this for maybe a few months, where I restart only when I "upgrade" (usually because of https://bugs.kde.org/show_bug.cgi?id=414553).
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Jul 01 17:22:09 computerName kwin_x11[1448]: file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/windowswitcher/WindowSwitcher.qml:58: TypeError: Cannot read property 'smallSpacing' of null
Jul 01 17:22:09 computerName kwin_x11[1448]: The X11 connection broke: I/O error (code 1)
Jul 01 17:22:09 computerName xembedsniproxy[1489]: The X11 connection broke (error 1). Did the X11 server die?
Jul 01 17:22:09 computerName kactivitymanagerd[1455]: The X11 connection broke (error 1). Did the X11 server die?
Jul 01 17:22:09 computerName gmenudbusmenuproxy[1501]: The X11 connection broke (error 1). Did the X11 server die?
Jul 01 17:22:09 computerName at-spi-bus-launcher[1752]: X connection to :0 broken (explicit kill or server shutdown).
Jul 01 17:22:09 computerName org.kde.Shutdown[1683509]: cannot connect to daemon at tcp:5037: Connection refused
Jul 01 17:22:09 computerName org_kde_powerdevil[1536]: The X11 connection broke (error 1). Did the X11 server die?
Jul 01 17:22:09 computerName kaccess[1481]: The X11 connection broke (error 1). Did the X11 server die?
Jul 01 17:22:09 computerName kglobalaccel5[1466]: The X11 connection broke (error 1). Did the X11 server die?
Jul 01 17:22:09 computerName kded5[1444]: The X11 connection broke (error 1). Did the X11 server die?
Jul 01 17:22:09 computerName kwin_x11[1448]: The X11 connection broke (error 1). Did the X11 server die?
Jul 01 17:22:09 computerName sddm[1230]: Display server stopping...
Jul 01 17:22:09 computerName sddm[1230]: Socket server stopped.
Jul 01 17:22:09 computerName sddm[1230]: Socket server stopping...
Jul 01 17:22:09 computerName sddm[1230]: Auth: sddm-helper exited successfully
Jul 01 17:22:09 computerName systemd-logind[1063]: Session 2 logged out. Waiting for processes to exit.
Jul 01 17:22:09 computerName sddm-helper[1310]: [PAM] Ended.
Jul 01 17:22:09 computerName kernel: audit: type=1104 audit(1593642129.248:1234): pid=1310 uid=0 auid=1000 ses=2 msg='op=PAM:setcred grantors=pam_tally2,pam_shells,pam_unix,pam_permit,pam_gnome_keyring acct="userName" exe="/usr/lib/sddm/sddm-hel>
Jul 01 17:22:09 computerName audit[1310]: CRED_DISP pid=1310 uid=0 auid=1000 ses=2 msg='op=PAM:setcred grantors=pam_tally2,pam_shells,pam_unix,pam_permit,pam_gnome_keyring acct="userName" exe="/usr/lib/sddm/sddm-helper" hostname=? addr=? termina>
Jul 01 17:22:09 computerName sddm-helper[1310]: pam_kwallet5(sddm:setcred): pam_kwallet5: pam_sm_setcred
Jul 01 17:22:09 computerName sddm-helper[1310]: pam_kwallet5(sddm:session): pam_kwallet5: pam_sm_close_session
Jul 01 17:22:09 computerName kernel: audit: type=1106 audit(1593642129.235:1233): pid=1310 uid=0 auid=1000 ses=2 msg='op=PAM:session_close grantors=pam_keyinit,pam_loginuid,pam_keyinit,pam_limits,pam_unix,pam_permit,pam_mail,pam_systemd,pam_e>
Jul 01 17:22:09 computerName audit[1310]: USER_END pid=1310 uid=0 auid=1000 ses=2 msg='op=PAM:session_close grantors=pam_keyinit,pam_loginuid,pam_keyinit,pam_limits,pam_unix,pam_permit,pam_mail,pam_systemd,pam_env,pam_gnome_keyring,pam_kwalle>
Jul 01 17:22:09 computerName sddm-helper[1310]: pam_unix(sddm:session): session closed for user userName
Jul 01 17:22:09 computerName sddm-helper[1310]: [PAM] Closing session
...
Jul 01 17:22:08 computerName kdeconnectd[1504]: kdeconnect.plugin.notification: Destroying NotificationsPlugin
Jul 01 17:22:08 computerName kwin_x11[1448]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 44584, resource id: 31457285, major code: 18 (ChangeProperty), minor code: 0
Jul 01 17:22:08 computerName polkit-kde-authentication-agent-1[1493]: Removing listener  PolkitQt1::Agent::Listener(0x60099da9d220)
Jul 01 17:22:08 computerName polkitd[1478]: Unregistered Authentication Agent for unix-session:2 (system bus name :1.39, object path /org/kde/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8)
Jul 01 17:22:08 computerName polkit-kde-authentication-agent-1[1493]: Destroying listener
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: client disconnected
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: client connected
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: waitingForEnvironment on: 3
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: Waiting for hash on 7-
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: Got pam-login param
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: Checking for pam module
Jul 01 17:22:08 computerName kwin_x11[1448]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 44580, resource id: 29360144, major code: 18 (ChangeProperty), minor code: 0
Jul 01 17:22:08 computerName dbus-daemon[1339]: [session uid=1000 pid=1339] Successfully activated service 'org.kde.Shutdown'
Jul 01 17:22:08 computerName kwin_x11[1448]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 44572, resource id: 4194339, major code: 18 (ChangeProperty), minor code: 0
Jul 01 17:22:08 computerName dbus-daemon[1339]: [session uid=1000 pid=1339] Activating service name='org.kde.Shutdown' requested by ':1.13' (uid=1000 pid=1464 comm="/usr/bin/ksmserver ")
...
Jul 01 17:22:09 computerName kernel: audit: type=1104 audit(1593642129.248:1234): pid=1310 uid=0 auid=1000 ses=2 msg='op=PAM:setcred grantors=pam_tally2,pam_shells,pam_unix,pam_permit,pam_gnome_keyring acct="userName" exe="/usr/lib/sddm/sddm-hel>
Jul 01 17:22:09 computerName audit[1310]: CRED_DISP pid=1310 uid=0 auid=1000 ses=2 msg='op=PAM:setcred grantors=pam_tally2,pam_shells,pam_unix,pam_permit,pam_gnome_keyring acct="userName" exe="/usr/lib/sddm/sddm-helper" hostname=? addr=? termina>
Jul 01 17:22:09 computerName sddm-helper[1310]: pam_kwallet5(sddm:setcred): pam_kwallet5: pam_sm_setcred
Jul 01 17:22:09 computerName sddm-helper[1310]: pam_kwallet5(sddm:session): pam_kwallet5: pam_sm_close_session
Jul 01 17:22:09 computerName kernel: audit: type=1106 audit(1593642129.235:1233): pid=1310 uid=0 auid=1000 ses=2 msg='op=PAM:session_close grantors=pam_keyinit,pam_loginuid,pam_keyinit,pam_limits,pam_unix,pam_permit,pam_mail,pam_systemd,pam_e>
Jul 01 17:22:09 computerName audit[1310]: USER_END pid=1310 uid=0 auid=1000 ses=2 msg='op=PAM:session_close grantors=pam_keyinit,pam_loginuid,pam_keyinit,pam_limits,pam_unix,pam_permit,pam_mail,pam_systemd,pam_env,pam_gnome_keyring,pam_kwalle>
Jul 01 17:22:09 computerName sddm-helper[1310]: pam_unix(sddm:session): session closed for user userName
Jul 01 17:22:09 computerName sddm-helper[1310]: [PAM] Closing session
...
Jul 01 17:22:08 computerName kdeconnectd[1504]: kdeconnect.plugin.notification: Destroying NotificationsPlugin
Jul 01 17:22:08 computerName kwin_x11[1448]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 44584, resource id: 31457285, major code: 18 (ChangeProperty), minor code: 0
Jul 01 17:22:08 computerName polkit-kde-authentication-agent-1[1493]: Removing listener  PolkitQt1::Agent::Listener(0x60099da9d220)
Jul 01 17:22:08 computerName polkitd[1478]: Unregistered Authentication Agent for unix-session:2 (system bus name :1.39, object path /org/kde/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8)
Jul 01 17:22:08 computerName polkit-kde-authentication-agent-1[1493]: Destroying listener
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: client disconnected
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: client connected
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: waitingForEnvironment on: 3
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: Waiting for hash on 7-
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: Got pam-login param
Jul 01 17:22:08 computerName sddm[1333]: kwalletd5: Checking for pam module
Jul 01 17:22:08 computerName kwin_x11[1448]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 44580, resource id: 29360144, major code: 18 (ChangeProperty), minor code: 0
Jul 01 17:22:08 computerName dbus-daemon[1339]: [session uid=1000 pid=1339] Successfully activated service 'org.kde.Shutdown'
Jul 01 17:22:08 computerName kwin_x11[1448]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 44572, resource id: 4194339, major code: 18 (ChangeProperty), minor code: 0
Jul 01 17:22:08 computerName dbus-daemon[1339]: [session uid=1000 pid=1339] Activating service name='org.kde.Shutdown' requested by ':1.13' (uid=1000 pid=1464 comm="/usr/bin/ksmserver ")
Jul 01 17:22:06 computerName ksmserver-logout-greeter[1683490]: qt.svg: <input>:663: Could not resolve property: #radialGradient3505
...
Jul 01 17:22:06 computerName ksmserver-logout-greeter[1683490]: file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/components/UserDelegate.qml:41: ReferenceError: config is not defined
...
Jul 01 17:22:06 computerName ksmserver-logout-greeter[1683490]: qt.svg: <input>:663: Could not resolve property: #radialGradient3118
Jul 01 17:22:06 computerName dbus-daemon[1339]: [session uid=1000 pid=1339] Successfully activated service 'org.kde.LogoutPrompt'
Jul 01 17:22:05 computerName dbus-daemon[1339]: [session uid=1000 pid=1339] Activating service name='org.kde.LogoutPrompt' requested by ':1.13' (uid=1000 pid=1464 comm="/usr/bin/ksmserver ")
Jul 01 17:22:02 computerName kwin_x11[1448]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 43702, resource id: 69377923, major code: 18 (ChangeProperty), minor code: 0
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