I just noticed the same thing.

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

Thanks for this info! Very helpful