Also, on the bug that Sensou Shin said, both rankings and the Beatmap status are not shown. I guess it's like osu! doesn't recognize the map at all when the filters are activated and that map doesn't need to be shown.
Also, if you wait for the song that you have selected (the one what is out of range of the filters) to end, another song will play, and this one is gonna allow you to play it, even if it's not on the Beatmap panels. (the osu! logo starts to go at the BPM rhythm and the rankings are shown.) If you change the Grouping when this song is being played is gonna bug again, but this one will replay, not like the other one.
I hope I have not explained it too badly...
Also, if you wait for the song that you have selected (the one what is out of range of the filters) to end, another song will play, and this one is gonna allow you to play it, even if it's not on the Beatmap panels. (the osu! logo starts to go at the BPM rhythm and the rankings are shown.) If you change the Grouping when this song is being played is gonna bug again, but this one will replay, not like the other one.
I hope I have not explained it too badly...