This was certainly a kernel bug. Upgrading to linux-image-6.18.9+deb14-amd64 fixes it.
- Bug#1127001: xserver-xorg: X server crashes on screen l... SpikeTheHobbitMage
- Bug#1127001: Was kernel bug. Fixed in kernel 6.18.... spike
This was certainly a kernel bug. Upgrading to linux-image-6.18.9+deb14-amd64 fixes it.