Does it happen when you try to launch it from the KRunner-powered search in Kickoff too? Or just KRunner itself?

So far I haven't seen this problem with Kickoff, but I rarely use it and when I tried, it worked. Also in KRunner this only happens sometimes. Not every time. For example yesterday everything was fine, but today I had problem with 1st start of teams snap, but second work OK.

Logs:

failed:
jan 14 08:58:29 hostname systemd[1426]: Started snap.teams.teams.386180cf-603b-4ad0-80df-eb3b979a9419.scope.
jan 14 08:58:29 hostname systemd[1426]: Started Microsoft Teams - Preview.
jan 14 08:58:29 hostname audit: BPF prog-id=28 op=LOAD
jan 14 08:58:29 hostname audit[4718]: SYSCALL arch=c000003e syscall=321 success=yes exit=9 a0=5 a1=7ffcaa71eb80 a2=78 a3=0 items=0 ppid=4665 pid=4718 auid=1000 uid=1000 gid=1000 euid=0 suid=0 fsuid=0 egid=0 sgid=1000 fsgid=0 tty=(none) ses=3 comm="snap-confine" exe="/usr/lib/snapd/snap-confine" key=(null)
jan 14 08:58:29 hostname audit: PROCTITLE proctitle=2F7573722F6C69622F736E6170642F736E61702D636F6E66696E65002D2D6261736500636F7265313800736E61702E7465616D732E7465616D73002F7573722F6C69622F736E6170642F736E61702D65786563007465616D73
jan 14 08:58:29 hostname krunner[4718]: /user.slice/user-1000.slice/user@1000.service/app.slice/app-teams_teams-07c16d4139d64b3d89473a65f1c7cb32.scope is not a snap cgroup
jan 14 08:58:29 hostname audit: BPF prog-id=0 op=UNLOAD
jan 14 08:58:29 hostname kernel: audit: type=1334 audit(1642147109.814:190): prog-id=28 op=LOAD
jan 14 08:58:29 hostname kernel: audit: type=1300 audit(1642147109.814:190): arch=c000003e syscall=321 success=yes exit=9 a0=5 a1=7ffcaa71eb80 a2=78 a3=0 items=0 ppid=4665 pid=4718 auid=1000 uid=1000 gid=1000 euid=0 suid=0 fsuid=0 egid=0 sgid=1000 fsgid=0 tty=(none) ses=3 comm="snap-confine" exe="/usr/lib/snapd/snap-confine" key=(null)
jan 14 08:58:29 hostname kernel: audit: type=1327 audit(1642147109.814:190): proctitle=2F7573722F6C69622F736E6170642F736E61702D636F6E66696E65002D2D6261736500636F7265313800736E61702E7465616D732E7465616D73002F7573722F6C69622F736E6170642F736E61702D65786563007465616D73
jan 14 08:58:29 hostname kernel: audit: type=1334 audit(1642147109.814:191): prog-id=0 op=UNLOAD

started:
jan 14 08:59:22 hostname systemd[1426]: Started snap.teams.teams.14e7f1d0-3854-42bd-bdd4-6cb24246f0b5.scope.
jan 14 08:59:22 hostname audit: BPF prog-id=29 op=LOAD
jan 14 08:59:22 hostname kernel: audit: type=1334 audit(1642147162.758:203): prog-id=29 op=LOAD
jan 14 08:59:22 hostname kernel: audit: type=1300 audit(1642147162.758:203): arch=c000003e syscall=321 success=yes exit=9 a0=5 a1=7ffeba1843c0 a2=78 a3=0 items=0 ppid=4665 pid=6827 auid=1000 uid=1000 gid=1000 euid=0 suid=0 fsuid=0 egid=0 sgid=1000 fsgid=0 tty=(none) ses=3 comm="snap-confine" exe="/usr/lib/snapd/snap-confine" key=(null)
jan 14 08:59:22 hostname kernel: audit: type=1327 audit(1642147162.758:203): proctitle=2F7573722F6C69622F736E6170642F736E61702D636F6E66696E65002D2D6261736500636F7265313800736E61702E7465616D732E7465616D73002F7573722F6C69622F736E6170642F736E61702D65786563007465616D73
jan 14 08:59:22 hostname audit[6827]: SYSCALL arch=c000003e syscall=321 success=yes exit=9 a0=5 a1=7ffeba1843c0 a2=78 a3=0 items=0 ppid=4665 pid=6827 auid=1000 uid=1000 gid=1000 euid=0 suid=0 fsuid=0 egid=0 sgid=1000 fsgid=0 tty=(none) ses=3 comm="snap-confine" exe="/usr/lib/snapd/snap-confine" key=(null)
jan 14 08:59:22 hostname audit: PROCTITLE proctitle=2F7573722F6C69622F736E6170642F736E61702D636F6E66696E65002D2D6261736500636F7265313800736E61702E7465616D732E7465616D73002F7573722F6C69622F736E6170642F736E61702D65786563007465616D73
jan 14 08:59:22 hostname systemd[1]: tmp-snap.rootfs_1hZDLg.mount: Deactivated successfully.
jan 14 08:59:22 hostname systemd[1426]: Started Microsoft Teams - Preview.
jan 14 08:59:22 hostname kwin_x11[1696]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 33565, resource id: 98566312, major code: 18 (ChangeProperty), minor code: 0
jan 14 08:59:22 hostname audit: BPF prog-id=0 op=UNLOAD
jan 14 08:59:22 hostname kernel: audit: type=1334 audit(1642147162.901:204): prog-id=0 op=UNLOAD
jan 14 08:59:23 hostname kwin_x11[1696]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 33920, resource id: 98566313, major code: 18 (ChangeProperty), minor code: 0
jan 14 08:59:29 hostname kwin_x11[1696]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 34571, resource id: 16780531, major code: 18 (ChangeProperty), minor code: 0
jan 14 08:59:29 hostname kded5[1695]: Registering ":1.100/org/ayatana/NotificationItem/Microsoft_Teams___Preview1" to system tray
jan 14 08:59:29 hostname plasmashell[1762]: QFont::setPointSizeF: Point size <= 0 (0.000000), must be greater than 0
jan 14 08:59:29 hostname pipewire-pulse[2094]: mod.protocol-pulse: client 0x55c8ffc9e1d0 [Chromium]: ERROR command:-1 (invalid) tag:2 error:25 (Input/output error)
jan 14 08:59:29 hostname wireplumber[2093]: <WpSiStandardLink:0x55855d5c9c00> si-standard-link: in/out items are not valid anymore
jan 14 08:59:32 hostname kwin_x11[1696]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 35715, resource id: 104857608, major code: 15 (QueryTree), minor code: 0

Thanks. That's odd.

After another week of testing I still haven't seen the problem with Kickoff. But I saw that KRunner wouldn't start Spotify twice in the row and then Kickoff started it.

I can reproduce this issue.

In my example, my Firefox is installed as snap to /snap/bin/firefox and Alt-F2 (Krunner) won't launch the browser (either by typing an URL or "firefox" directly). But when I change the application command in the plasma menu (the application entry command) to /usr/bin/firefox (which is actually a kubuntu script to launch /snap/bin/firefox) instead of the snap-executable, it works fine!

So there must be some issue with KRunner and snaps… hmmm…

I have the same problem in KickOff and Krunner. I think I have narrowed down the conditions for the problem to occur - it seems to be connected to whether Krunner/Kickoff are still loading the menu entries while pressing "Enter" :

STEPS TO REPRODUCE
1. Have a graphical snap application (I'll use the example of signal-desktop, but have observed this for all snap applications) installed
2. Open Kickoff and start typing "sign"
3. The application "Signal" is now selected as the topmost result. Quickly press enter to select it.

OBSERVED RESULT
Nothing happens. When plasmashell was started via terminal, the following message is displayed:
"Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
/user.slice/user-1000.slice/user@1000.service/app.slice/app-signal\x2ddesktop_signal\x2ddesktop-e7fbed6a9fe04518bed23e43793f11db.scope is not a snap cgroup"


EXPECTED RESULT
Signal is opened. It is worth noting that the behaviour changes when following these slightly different steps:
1. Open KickOff
2. Type "sign"
3. Wait until all entries are displayed and there's no more "movement" in the suggestion list.
4. Press enter -> Signal is opened

Signal is also opened as expected when it had been opened (and closed) in the same session before.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Kubuntu 24.04, 
KDE Plasma Version: Plasma 5.27.11
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.13

I think it might be the same problem as this one: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/2011806