What’s your graphics card?
Maybe enabling the hardware acceleration will help with this issue, but enabling the hardware acceleration should be already possible after updating your graphics card driver and I’m not sure why it didn’t work.
Maybe install OpenGL Extensions Viewer from GLView: Advanced OpenGL and Vulkan Diagnostics - RealTech VR to check OpenGL version. Clicking the download link didn’t work for me for some reason, but using the download url from that link strangely worked just fine.
The link is a redirect and the file will be downloaded from https://files.v3x.net/glview612-setup.exe
This is from the article How To: Check the Graphics Card Type and OpenGL Version about how to check OpenGL version.
The OpenGL website https://www.opengl.org/ also mentions Mesa3D after clicking on Download OpenGL, maybe it’ll help to enable hardware acceleration too, but I’m not sure and there’s no official Windows binary, but Platform specifics: Windows - OpenGL Wiki mentions Releases · pal1000/mesa-dist-win · GitHub and it seems to be safe to install.
The issue seems to be identical to Reddit - Dive into anything and there seems to be a fix. As I understand it, it means enabling the hardware acceleration.
Changes - Changes
I fixed it, followed those steps above with “angle” instead of auto, you should try all three and see which works for you
The similar report with a gif mentions that temporarily minimizing Anki window helps to fix probably the rendering bug:
https://www.reddit.com/r/Anki/comments/iee8fk/bug_resulting_in_sometimes_not_displaying_answers/