That's not a bug, by default, /list hides non-text channel, see
https://forums.mirc.com/ubbthreads.php/topics/241692/Channels_that_begin_with_do_no#Post241692, you need to uncheck the option (alt + l > hides non-text channels)
Khaled, could we have this turned off by default? It really confuses people more than it helps.