If you click on the blue dot then it will show you exactly where the issue is by underlining, see the example below.
It would be useful to see in your case.
I understand that Name has 133 rows, so until you get to 500 rows then the blue dot is not a problem.
In any case, PA Studio may be confused by the disambiguation operator, so you could try this syntax:
AddColumns(Opportunity; "Name"; Lookup (Name; NameID = Opportunity[@NameID]))
This should still work, but may remove the blue dot.
If it does not remove the blue dot or does not work, then you could try to change one of the column names so that you do not need disambiguation. This may remove the bule dot, but not guaranteed.
Please let me know
It does not appear as though disambiguation has been resolved for delegation (specifically dealing with > 500 records).
Any thoughts on whether it will be happening?