I've never had any problems with the Atari 50, but since I updated to the latest version and installed the DLC, the game has some nasty glitches, especially in the timeline menus. I tried uninstalling and reinstalling the game, but to no avail.

My PC:
Intel Core i5-13400F
16GB RAM
NVIDIA GeForce RTX 4060

Which version of the file are you using what is its number? 1.05 (84083)? offline installer? galaxy?

Yes, I'm using version 1.05_gog from GOG Galaxy.
I also tried playing in a window, but that didn't help.
I also have the problem when playing videos. Everything glitches and it looks like an old-fashioned Android keyboard.

I use the offline installer (only with client galaxy it works) and the game works fine for me, only some games in the collection don't work properly.
The GOG Galaxy client must also be installed for the game to run (offline installer) but I run game not through gog galaxy client.