I just created a document library and invited a guest user with edit-access. Created a customized meta-data field and added some terms in the termset. Then added three files and attached the terms to them.
The owner & other internal user can view the terms that has been set on the items in the library. But guest users cannot.
Can anyone else reproduce this strange behavior and what could possibly be wrong?
Edit: I just reproduced this in another tenant. No solution though.