Why doesn't the auto-populate work in all Dynamic Views?

I have several Dynamic Views in WorkApps. On some of the dynamic views I can @mention someone in the comments and their name will auto-populate...

But on other dynamic views it do NOT auto-populate...

I can type the full email address to add the mention but I must know the full email address.

Both source sheets are shared with Editing rights.

Thank you in advance.

Answers