Hi people,
has anyone got a fix for this, see pics.
Synced cams in first sequence,
Nested each track (cam) to a new sequence,
Then created a multicam sequence.
Worked well for about a min, then every time I hit play, I lose the multicam window and get one camera playing with a weird aspect ratio in a completely different part of the clip. Press stop and the multi cam window returns.

Ive seen that before are you using a Black Magic card? I would get that with my BM card so I just used a standard sequence for my multi-cam to work around the problem.

You have an extra step I don't understand. Why not just sync everything, then alt-select all the image tracks together, and nest them. Why nest each track first?

I always nest each track( camera) first for CC ease.
If it's a 2+ hr event I may have 6 or 7 cam files on one track, it's much easier for me to correct one cam in one go rather than having to copy and paste each time I tweak it.

Randy, yes it is a BM Intensity card.
Updated BM software and haven't seen it since.
All good now.