Quoting rules in the markup language we use might be tripping you up
It sounds like you are running into quoting rules in TOML, the markup language we chose to use for defining autoextractors in files. When you wrap a regex in double quotes, the TOML parser attempts to go in and expand the escaped characters itself, when what we *really* want is to pass those backslash escapes into the regex module verbatim.
Luckily, if you change the double quotes to single quotes, TOML will not expand the escapes.
Still having trouble? Feel free to send your .ax file over to firstname.lastname@example.org and we can take a look.