The Assembly File was rolled back, but all the parts kept the latest version.

I tried. The steps are listed below:
Before Check out,
1. Select Assembly file
2. Click history
3. Click Get and select previous version
4. Close window form
5. Select two parts (Tried to skip)
6. Get previous version (Tried to skip)
7. Double click assembly file and check out all of the parts
8. Rebuild Assembly file

The check-out list showed that two parts would be gotten previous version.
However, the latest version was applied after “rebuild” assembly file.

After Check out,
1. Click parts in the assembly file
2. Click parts properties
3. Click Get and select previous version for two parts
4. Confirm replacement
5. Mate error still exist
6. Check those errors and find “face invalid” from replaced parts

I checked Contains of the Assembly file after all above steps. All of the parts still kept latest version. Nothing changed.

Please help. Thanks.