3802766 - My Import User to Group Mapping through BTP shows a Records updated count, but the groups do not appear, while a manual import works

Through BTP, I run Import User to Group Mapping using the Import Batch Data task. The import summary shows a non-zero Records updated count, but the group memberships do not appear in the user interface, or only one group appears.

Importing the same file manually through the Buyer user interface updates the memberships correctly.

No error message appears.

groupconsolidated.csv, batch import, master data import, membership not saved, group not showing, user not added to group, bulk user import, group membership import, data load operation, integration import , KBA , BNS-ARI-CP-CORE-UM , Core Administration User Management , BNS-ARI-CP-CORE-IEX , Core Administration Import/Export , Problem