NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
In the overview effect, you cannot drag windows from one monitor to another in multimonitor setups. Overview shows on all monitors with the apps showing on the correct monitor, which is great. Just need to be able to move them to a different one.
As an aside, I realize that you can drag from the actual monitor to the other, but this would still be very useful when you have a lot of applications open at the same time.
STEPS TO REPRODUCE
1. activate overview with at least two active monitors
2. try to move an application to another monitor.
The application does not move and goes right back to the starting place in the overview effect.
The application should move to the expected monitor.
Linux/KDE Plasma: opensuse tumbleweed
(available in About System)
KDE Plasma Version: 5.24.0
KDE Frameworks Version: 5.90.0
Qt Version: 5.15.2
*** This bug has been marked as a duplicate of bug 448566 ***