If you have your list field configured to display choice values in a list, does it work correctly if you display it as a reference type?  Can you take a screenshot of your dictionary entry for this field and post it?

If changing to a reference and some table, all is directly fine.
Also nothing fancy on the field, It's just plain new nothing added besides choices.

Hmmmmm...
Might the field type 'List' not be intended for using choices? Docs is mentioning "Reference field that accepts multiple references rather than just one". Also did a check on my developer instance, could not find a single example of a List field with choices.

Maybe I'm on the wrong track? And should use a reference on the list field?

It would be possible with renaming the choices, though then I would get labels with spaces, slashes etc which is bad practice 🙂

Just switched to a reference type and a new referencing table. All fine!

This behavior is still present out of the box in orlando, so looks like a bug they just don't intend to fix.