Solo not working in sequencer

[KroArp]

What I mean : When I press the blue Solo for one track, the other tracks with the same MIDI cannel also sound, but they obviously shouldn't ( If I use a different MIDI channel, the timbre that I chose for soloing, doesn't sound for recording or playing ). All timbres on the same MIDI channel are sounding when I put a new timbre for use and I solo it. They sound after the song is already recorded ( and now playing ) and they sound when I use the new timbre - I repeat : even if I solo it.
What's happening ?