SUMMARY
Any action "lags" one action behind in the "action" queue on Wayland. This problem was introduced with the latest packages update on the 16th June 2021 and affects all launching or opening operations. This issue doesn't seem to occur on X11. Unfortunately this issue renders the Wayland desktop close to unusable at the moment.

STEPS TO REPRODUCE
1. Regular start into the Wayland based desktop session
2. First time trying to launch any application doesn't do anything
3. Trying to launch a different application results in launching the previously selected application (step 2)
4. This cycle then continues throughout the session

EXAMPLE
Following the initial startup of the system the following happens:
-> Select Firefox to start doesn't do anything
-> Then selecting Thunderbird would open Firefox
-> Then selecting Dolphin would launch Thunderbird
-> and so on...

OBSERVED RESULT
Selected application or opening action should launch the application.

EXPECTED RESULT
The previously selected application gets launched instead of the intended one

SOFTWARE/OS VERSIONS
Windows: n/a
macOS: n/a
Linux/KDE Plasma: 5.4.0-74 Kernel
(available in About System)
KDE Plasma Version: 5.22.1
KDE Frameworks Version: 5.83.0
Qt Version: 5.15.3

ADDITIONAL INFORMATION
No hints or errors related to this issue were found in the logs.