When removing a User Defined Field association in PSA, the corresponding Field will be removed from related Upland Analytics View(s) and from any report(s) built with this Field prior to the removal.
Note that upon running a report containing this Field, you will get the following error message: One of the fields in this report is not configured properly or is no longer available for reporting. (UA_DT_USERFUNCTIONALGROUPLIST_Astazi_Selection)
This is the expected behavior in Upland Analytics. You must Edit the report and click Save (no changes in report designer are required).