Plan type is not set

Summary:

While using forms in SmartView users have started to get an error "Plan type is not set" when trying to select the entity from the POV ribbon.

Content (required):

We are using two entities - a parent and a child - in the POV for the forms. This works OK on some of our forms but not on others and we can't find any guidance to explain what we are doing wrong.

Version (include the version you are using, if applicable):

SmartView 21.200 (although some users are now on 22.100)

Code Snippet (add any code snippets that support your topic, if applicable):