I made working regex on the linked website https://regex101.com , but it didn't work in this extension. It's unclear what format of regex FA Blacklist uses, and it doesn't seem to be the default regex of regex101.com. I don't really know what to do.
My keyword was /.*(diaper).*/gmi, which successfully finds every line with "diaper" in the name on regex101.com. In FA Blacklist, nothing happens when I use this with a blacklist filter in a user's gallery. "Scan submission titles for keywords" is on, as well as the filter itself.
I don't know if my problem is that I don't have the right syntax, or if it's that it just isn't working. I hope this can be fixed, I'd really appreciate it!