If one of tag group settings
Is set to a different group then the reviewable topic’s owner. Then the topic cannot be approved with that tag.
review every postsite settings for testing.
Create a tag group with a tag and set the Tags are visible only to the following groups e.g: staff
Create a topic with a non staff user. I created with a TL1 user.
Click edit and add the tag you created on the 2. point.
Click Approve Post button.
It will show a warning modal.
And a console error.
It seems on review page it restricted to the topic owner privileges.