I've got a very similar issue to poppers up above, the difference being that I don't see any graphical issues when alt tabbing.
I'm on Ubuntu 22.04, kernel 5.15.0-53-generic
I had a very similar error pop up:
018c:err:ntdll:RtlpWaitForCriticalSection section 7BC62360 "dlls/ntdll/loader.c: loader_section" wait timed out in thread 018c, blocked by 00fc, retrying (60 sec)
0190:err:ntdll:RtlpWaitForCriticalSection section 7BC62360 "dlls/ntdll/loader.c: loader_section" wait timed out in thread 0190, blocked by 00fc, retrying (60 sec)
0104:err:ntdll:RtlpWaitForCriticalSection section 7BC62360 "dlls/ntdll/loader.c: loader_section" wait timed out in thread 0104, blocked by 00fc, retrying (60 sec)
Here's the output for lspci | grep VGA
01:00.0 VGA compatible controller: NVIDIA Corporation GM206 [GeForce GTX 960] (rev a1)
Here's the output for glxinfo | grep OpenGL
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: NVIDIA GeForce GTX 960/PCIe/SSE2
OpenGL core profile version string: 4.6.0 NVIDIA 470.141.03
OpenGL core profile shading language version string: 4.60 NVIDIA
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 4.6.0 NVIDIA 470.141.03
OpenGL shading language version string: 4.60 NVIDIA
OpenGL context flags: (none)
OpenGL profile mask: (none)
OpenGL extensions:
OpenGL ES profile version string: OpenGL ES 3.2 NVIDIA 470.141.03
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20
OpenGL ES profile extensions:
I've tried launching into realms without existing characters, repairing client, uninstalling addons, installing dxvk, setting graphics settings to the minimum, turning off vsync, trying every renderer, and uninstalling/reinstalling, but to no avail.