SUMMARY
The Application Dashboard is slow to open, especially on first boot where it often fails to appear. The key to summon it (in my case, the Super key) needs to be pressed 2-3 times for it to actually open. After this, pressing the key to summon it will work the first time, every time for that session, but there is about a second of delay until it actually appears.

I am experiencing this on my Arch PC, but I can also reproduce this problem on my laptop running endeavourOS (although I don't primarily use the Application Dashboard on that machine).

Note that I have fade transitions turned off on my machines for this test (I have them enabled on my laptop usually but disabled them for testing, and I have them disabled on my desktop). 

STEPS TO REPRODUCE
1. Press key to open Application Dashboard, or click on the widget to open it.
2. The first 1-2 attempts will fail, but but third should succeed.
3. After this, close the Application Dashboard.
4. Attempt to summon the Application Dashboard again.
5. There will be a noticeable delay of around 1 second before it actually appears.

OBSERVED RESULT
The Application Dashboard is inconsistent and slow to open.

EXPECTED RESULT
The Application Dashboard should be snappy.

SOFTWARE/OS VERSIONS
SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.3.2
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2
Graphics Platform: Wayland

ADDITIONAL INFORMATION
- Possibly related to 499849.
- There is interestingly a similar delay when showing the "Lock/Logout" overlay.
- Another similar delay can be observed when opening KRunner, but that is for a separate bug report :-)