Theyre called respectables. I'll vote for this option, I'd love to be able to play with builds on the fly with the traainer in SP, so I know what to use in MP.
Delete trainer and all files in
Learn how to make your own Trainer Cleaner for the above paths Here. Link
Reboot PC to clear excess memory, get a fresh copy of latest trainer and extract it. Run trainer as admin, read the instructions and try again. At times, a new game may be needed to resolve failed options if the data in your save file was altered. Use on a new game and test the option. If it now works, quit to main menu and load your save and try it again.
Gain some XP, go into a menu where it shows and see if the ?? change.