Hi Cameron,2 things you can check:1. If you have 2 GA tool withn your
DTM web-property ( you are trying to migrate ) with same account ID.2.
If the GA account has "Enable EU compliance for Google Universal
Analytics" checked.I faced the similar issue with 2nd scenario in place.
I unched the "Enable EU compliance for Google Universal Analytics"
setting and it worked.ThanksAtul