Created attachment 153366 [details]
WAYLAND_DEBUG with 2s start delay - search for /[ 532235.427] wl_callback@24.done(1214)/

SUMMARY
Hi,
Using konsole as a test case, there is a noticeable lag to display the window:

o At first start up
o After some period of time (e.g. a minute) between new window starts

I have captured some WAYLAND_DEBUG=1 output showing lag vs no lag.

This is an excerpt of the debug when I observed the a two second lag:

[ 532235.418] wl_drm@25.format(1448695129)
[ 532235.423] wl_drm@25.capabilities(1)
[ 532235.427] wl_callback@24.done(1214)
#
# After running konsole in another window, the /tail -f/ paused above.  
# No window was displayed for about two seconds.
#
[ 534388.338]  -> wl_display@1.get_registry(new id wl_registry@24)
[ 534388.428]  -> wl_display@1.sync(new id wl_callback@26)
[ 534391.580] wl_display@1.delete_id(26)
[ 534391.586] wl_registry@24.global(1, "wl_compositor", 5)

SET UP
1. Create a new Linux user whose shell is /bin/bash
2. Log in to the new user using Wayland

STEPS TO REPRODUCE
Repeated make the following call, ctrl-D the new window to exit.  To observe the start delay, wait about 30 seconds between the calls:

   WAYLAND_DEBUG=1 konsole >> konsole.wayland_debug 2>&1

OBSERVED RESULT
When a new konsole window is started /shortly/ after a previously started konsole window, there is no observable delay.

However, if there's a 30 second delay between calls, a start delay is observed.

EXPECTED RESULT
The windows should start immediately.  As observed on X11.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 6.0.5-1-default
(available in About System)
KDE Plasma Version: 5.26.2
KDE Frameworks Version: 5.99.0
Qt Version: 5.15.6

ADDITIONAL INFORMATION