Hi,
If there was a direct change on the code via FTP by me, then a plugin update would definitely override that. Do you happen to have a back-up copy of the affected files by any chance from the last few months?
I’m asking because I don’t fully remember what exactly I did, as I answered a couple of hundred tickets in the meantime. I recall it was something with a custom field priority, but I am not exactly sure what it was.