The issue I believe is because I shared the feature service from ArcGIS Pro. After starting over in ArcMap 10.6.1, publishing a new feature, creating a new form from the feature service (removing fields, repeats and adding the hidden fields) and the custom URL. It finally worked.
Custom URL: arcgis-survey123://?itemID=cd09f873f02640f89270e5477b66d819&field:UNITID={UNITID}&field:Collector_GlobalID={GlobalID}
Attached is final xlsx file