Your world was apparently used on a Forge server and also with Fabric in the past. Removing mods is similarly bad as downgrading, all kinds of things can go wrong that way. Even if a Vanilla bug causes this item frame behaviour, it would not be valid on the bug tracker.
Tracking down exactly what is wrong in that world is very difficult (I tried the usual things, they didn't help), so I would recommend using the "recreate world" button in the world selection screen on your world, exiting the newly created world again and copying the folders
DIM1 (End) and
datapacks over to the new world. That should keep the most important things, while avoiding the item frame issue to creep in. You will have to recreate scoreboards and some other things, but the main parts of the world are saved.
If you want to put in more effort and actually find the exact cause, you can take one folder at a time from your old world and overwrite the folder in the new world with it. Once the problem occurs again, make a new world, copy everything that you know works and proceed by copying over the sub-folders of the problematic folder or the files in it. Once you found the file that causes the issue, you can compare it with a working one in NBTExplorer.