Have you tried changing your game resolution and display mode, or lowering your graphics settings, to see if that would make a difference?
What about the UI scaling in the Game section of the options?
Maybe check for updated video drivers.
As a partial workaround, you should usually be able to move your screen focus somewhere not too far away that the characters can not move, before doing anything in the inventory.
Please email supportdos@larian.com, with a description of the problem and the report.zip file generated by the
D:OS support tool (for the PC version). The report will contain system and game information, as well as your saved games. To reduce the file size, all but one save can be deleted from the zip.
For Mac, to get system specs you can use the 'System Report' button from the 'About This Mac' Apple menu item or the 'System Information' app (in the utilities folder).
Saves can be zipped by right clicking the folder(s) and selecting Compress, in the folder:
~/Documents/Larian Studios/Divinity Original Sin/PlayerProfiles/<ProfileName>/Savegames