Solo button turns on mute

I am a new cubasis user. IPad Air, Cubasis 1.7. Apogee One.
Not sure if it’s something I did, but at some point when playing back, pressing the SOLO button on a track no longer Mutes all the others, instead, it Mutes the track that I want to hear SOLO. Odd.
Can no longer SOLO a track unless I mute all other tracks.
Any ideas. Having fun so far, this is a terrific bit of software.

More details on this… Experiencing the problem after importing 7 ogg files and dropping them onto track view. This all works fine and I can play all tracks fine, and the SOLO button mutes all the others as it should.

However, this doesn’t last, so as first reported, pressing SOLO button on a track Mutes THAT track and not the others.

Any comments would be welcome. Hair pulling has commenced.