idk why, no error in console, nothing

survival too, not creative

I believe it's on purpose.
This issue is from some months now, but I leave this here for any other person who might end up looking for help on the same issue:

You can't get the maps out of the bundle. However, right-clicking the bundle on an item frame will place the maps automatically. You have to make the specific frame size for it to fit, and you can not retrieve the maps back. The bundle disappears too.

I believe this is a measure to avoid having players dupe bundles.