Hi NB2021deep,
Thank you for sharing what you recalled of your experience before this issue occured. If your Slot2 has a not been affected I would recommend keeping the backup of the file on USB so you can revert it if needed. However I do believe you need the .bin and profile files. Backing up to USB can allow you to redownload older versions of your save to your console, but players have mentioned that the issue has occured after reverting saves using backups so keeping a copy of the backups would be a good idea.
The instructions on the forums on how to share your save files with us for the team to investigate are the same steps for backing up your saves (Steps 1-10) if you want to make sure you have the correct files. [Save File Request]