Thanks again - both of you. Your willingness to help is amazing. It is reassuring Noel that you use EZD with BIAB songs without this issue.
No, I haven't used a downloaded Midi file in this song. It is only BIAB and then EZD added.
I have read up on ACID and am now looking to find where in Cakewalk there might be a means to disable it.
I am also looking on BandLab's help pages to check out what my settings should be for synchronisation. It suggests Trigger & Freewheel if my interface has a Word Clock input. I have a Steinberg UR44 and I don't think it has. So I am set up to use Full Chase Lock.
Then a setting : When SMPTE/MTC Timecode Is Detected (always switch clock source / do not switch clock source but start if in SMPTE/MTC mode / never switch). Now my brain is hurting, but I shall try the different options and come back to what it was set on
if changing these do not make a difference to my problem. It was set on Ask first, then switch clock source and start.
Then another setting choice : When clock source is set to SMPTE/MTC or MIDI Sync, pressing Play will : Switch current clock source and play back : OR : Maintain current clock source and wait for time code and I have to set either preference.
I guess I should be on Bandlab's forums to get advice on this.
If I stumble upon something I shall definitely come back with my findings.
All the best,
Chris