Application window fails to open on Ubuntu/Wayland

[BCSharp]

I've installed GearLever 2.0.4 from FlatHub on Ubuntu 22.04.4 using Wayland. When GearLever is started, its icon shows up in the taskbar, indicating it is running, but no window is visible on the screen. The application is responsive, e.g. I can close it by right-clicking its taskbar icon ans select Quit.

When I log into a session using X11 (the same system), GearLever works OK, so I suspect it is related to Wayland or XWayland.

When run from the command line, I get the following errors:

$ /usr/bin/flatpak run --branch=stable --arch=x86_64 --command=gearlever --file-forwarding it.mijorus.gearlever
Logging to file /home/bcsharp/.var/app/it.mijorus.gearlever/cache/logs/gearlever.log
libEGL warning: egl: failed to create dri2 screen
MESA: error: CreateSwapchainKHR failed with VK_ERROR_INITIALIZATION_FAILED
MESA: error: zink: could not create swapchain

The app does not crash, I can terminate it with Ctrl+C