Summary: Upon duplicating a set of tracks, one of them does not show up in the mixer with a live monitoring icon. The track fails to record. See screen shot.
Steps to recreate:
Created a project,
set recording to 24 bit recording depth,
added three tracks (track 1 routed channel 1; track 2 routed channel 2; track 3 routed channel 2 also but phase inverted; this amounts to middle-side microphone setup)
added a group, routing tracks 1-3 to it
added another track (routed channel 3, this was a direct instrument mic)
armed tracks and recorded successfully
Duplicated each of the existing tracks, erasing the recordings from the duplicates, moved the duplicates down below the first set
Routed the duplicate tracks into the new duplicate group
Attempted to arm each of the duplicated tracks
So now we have the original set: three tracks in a group plus a direct instrument mic
And a second set: three tracks in a group plus a direct instrument mic
The problem is, the last track now CANNOT be live monitored in the mixer and does not record. Viewed as a single channel, the live monitoring icon appears, but in the mixer it does NOT.
Expected to see a live monitoring icon in the mixer for the last track, a direct instrument mic, and to be able to record to it.
No live monitoring icon appears in the mixer for the last track. Recording to it does not work.
Delete the offending track and redefine it, not using duplication. Copy all effects settings to the newly created track.
Cubasis 3.0.2; Ipad Pro 128 GB with IOS 13.5.1