On non-English speaking forum there were posts about transfers between the accounts that ended with accounts closures. Legitimate transfers between family members.

Someone tried to transfer points to one account but there was no sign it went through, so tried to second family member account. In general, 4 transfers were made and only one worked, third one. After transfer was finally completed, Hilton closed all three accounts.

After user complained, he got information to contact hhfraudprotection, no one else wanted to help him and he haven't heard from anyone. Not sure if it was sorted by now, or not. It was posted 11 days ago. It's quite possible that person is member here so may update us.