https://en.wikipedia.org/wiki/Substitute_character
If the SFV file has the 0x1A character, the SRR file won't be created with pyReScene Auto. This is an issue with music releases.
It is mostly for iTS releases that have an original MorGoTH tag line. Some NFOs can contain the character too.
To confirm or test. Python 3 handles the characters better.
Example file with SUB char in SFV comment