Hello @pyro57, this issue was previously evaluated multiple times and https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/431 probably has the most technical details behind it.
On the Steam side of this, this issue is already being tracked at #8604. Closing in favor of the older issue report.
Your system information
Please describe your issue in as much detail as possible:
When Steam input loads in a Wayland session the cursor becomes invisible on the Steam Deck without an external mouse. The mouse is visible during an X11 session, and before steam is launched the trackpads work as expected, after steam launches the cursor becomes invisible when using the built in controls on the steam deck.
External mice show a visible cursor, and the mouse is still clearly working using the trackpads and joysticks on the steam deck as things highlight and clicking does indeed work, but the cursor is invisible. Its likely the same issue as this one Issue and has to do with steam input, but that issue was closed because of the ability to use 3rd party software to configure the controller instead of steaminput, which in my opinion is not a solution.
TLDR: Steam input mice (trackpad and joystick on the steamdeck) make the cursor invisible on wayland sessions. The cursor works fine until steam is launched then it becomes invisible.
Steps for reproducing this issue: