Random crashes 12.1 – 12-8.2

[Gruntos]

Good day all. Im a new member so if this has been discussed before please point me to the correct post and I will understand.

I have a mac pro (6,1) 32 mb memory connected to a MOTU 16A through thunderbolt. I am experiencing a total stoppage of processing audio after a random time which requires a Force quit followed by a restart to start again. There is no one thing that points to a failure as it is completely random.
Some times I can record for 3 hrs continuous with out problem then some times I get 20 mins and although the screen is still scrolling I see a flat line and nothing is being recorded. This is accompanied by the last second of recording being repeated infinitum although nothing is recording.

I work in a Radio studio and use pro tools to mix the live show with a Raven MTI.
I have 3 Aux tracks fed to a bus which is then recorded on a audio track. Output is fed back via aux tracks to the encoders and also to my monitors and headphones. I have used this setup for many years with Version 11 and now 12 and suddenly I start to get random crashes. I thought this was initially down to a faulty SSD, which was replaced. But the problem still persists.

I know this is a little vague but I don’t have much to go on as the crashes are total random. I have turned off disk indexing but the CPU usage and disk usages are so low not sure where else to look. When running I have 22 gb free and the cpu us running at 4% so nothing overtaxed. Disk speed is 500gb read write with 50% free.

I have tried with various buffer settings and setting I have tried Ignore errors, all have the same issues.

Any pointers would be great

Bob