GarageBand Glitch on iPad Pro 12.9 2021

We were happily making music on my plain and simple old iPad, when I thought it would be a good idea to turbocharge our output with a new sooper dooper iPad Pro. Big mistake.

Our first attempt at a song left us with a bizarre ghost track that we can't delete. It has an icon that looks like a yellow control knob and has titled itself 'Aux 1'. When we try to open up the song in GarageBand that was specifically created on this iPad, it gives us an error saying that the track contains features that are not available on this iPad - despite the fact that it WAS created on exactly THIS iPad! GarageBand then opens it up as a new track with a suffix of 'Copy 2' 'Copy 3' etc. When the song opens up, there are no tracks visible. If i add a new track, eg a new amp track, the tracks magically reappear.

I am severely underwhelmed and mightily p****ed off! Any ideas????