Hey guys,
Castlevania: DoS is the only game that has this problem so far.
I've backed up other saves to hard disk and then copied it to the microSD back with no problems.
However, this is what I did:
I backed up the save for DoS to my hard disk by copying the .dat file.
Then I traded souls...
btw i feel this a good time to remind you guys that sea of thieves was made by rare, who also made DKC1-3 and DK64, alongside banjo kazooie and conker's bad fur day