[Prangesco]

Sorry for bothering you @danbp,
I eventually solved this issue by myself and it was much easier than I thought.
I’m updating this so that you don’t lose time answering and in case it may be useful to somebody else.

As I guessed, I just needed to pass

remove_filter( ‘bp_after_has_profile_parse_args’, ‘flegmatiq_profiles’, ‘exclude_groups’ );

after the functions provided by @danbp in the link I posted above, still in bpcustom.php.
Apparently it cancelled the filter and fixed the problem.