EDIT: just checked in firefox, I don't see an issue. can you email me at me@dchuk.com and maybe I can debug with you?
UA being blocked for example:
Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:140.0) Gecko/20100101 Firefox/140.0
Allowed:
Opera/9.80 (Windows NT 6.1; U; zh-tw) Presto/2.7.62 Version/11.01 Opera/9.80 (Windows NT 5.1; U; cs) Presto/2.7.62 Version/11.01
Mozilla/5.0 (Windows NT 5.1) Gecko/20100101 Firefox/14.0 Opera/12.0 Mozilla/5.0 (Macintosh; Intel Mac OS X 14; rv:140.0) Gecko/20110101 Firefox/140.0
UA being blocked for example:
Did mess with it some more:Allowed:
406: Maybe just remove it?