HSDL Assignment Update-Upload Progress says Success. Assignment Page says No attribute changes found

Hi Experts,

We are using HSDL for mass assignment updates. The Upload Progress says Success. No errors. But when we go to employee assignment page and look at the record history, it says No attribute changes found.

This has created confusion because, if you believe the HSDL, the update happened. But when you look at the actual record, no changes were made

Has any one seen this issue? Any ways to fix it?