I ran into this issue after:
I didn't want to delete the OPC server connection, because I might want to re-use it at a later time.
Just for the sake of this report I did remove it and it worked including to dialog that asks to delete associated tags.
Solved! Go to Solution.
I'll pass this information to our CAR team and see if they have any input on this issue as it does seem to be something that's been overlooked.
We are currently processing this with CAR ID 743604, the target release to fix the bug is 19.6.