Lowercase filter doesn't seem to work properly

Hi

I don't seem to find a way, how to filter the song fields that have beginning in lowercase.
%field% MATCHES ^\l - doesn't work
%field% MATCHES ^[a-z] - doesn't work
%field% MATCHES ^\U - doesn't work
%field% MATCHES ^a - doesn't work (for beginning with specific letter - lowercase 'a')
%field% MATCHES ^\x{0061} - doesn't work (for beginning with specific letter - lowercase 'a')

It always returns matches regardles of uppercase or lowercase...

Does anyone have any idea or is it bug...

Best regards.

try a
%field% MATCHES (?-i)^\l
to find the lower case letters in the front

as a default mp3tag ignores any kind of case for the search pattern in the filter, so you have to force it every time.

Wow. Who would think. It acually works. Although I don't know why...
Anyway. Thank you...