SUMMARY
Using GTK apps while running KRDC seems to cause the menu drop down bar to crash. Sometimes it just disappears during the session and cannot be restored. have to alt+tab to another window and then unset fullscreen from the window context menu and then ctrl+shift+f a few times to restore the menu bar.

STEPS TO REPRODUCE
1. Start an RDP session in KRDC
2. 
  a) switch out of full screen, open a gtk app, switch back to full screen
  b) work for an indeterminate amount of time in rdp session, note that the menu bar goes missing. may have firefox or bash open sometimes when this happens, occasionally VLC (rpmfusion repo) and pulseeffects, not sure if other apps?
3. after an indeterminate amount of time, the menu bar goes missing, requiring manually exiting full screen with alt+tab (assuming you have another application open)

OBSERVED RESULT
menu drop down bar in rdp session goes missing/crashes (not autohidden)

EXPECTED RESULT
menu drop down bar remains in place until you exit full screen

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 32/KDE Plasma
(available in About System)
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.68.0
Qt Version: 5.13.2

ADDITIONAL INFORMATION