Resolve 20 - glitches on export from M1

My own fault for using a very basic M1 Air on a job (Mac based Premiere project with several TB across 3 drives) but I got several glitches on some exports - corrupted / repeated frames and flashes of 'media offline'.

May have been related to heat issues (Air was running in clamshell mode, media was UHD).

The Air actually did a pretty good job, up to this point, despite being the most basic spec.

(Ended up transferring to PC to export.)

Noting this here just in case anyone else sees a similar issue.

I see that sometimes with PC or Mac, usually deleting the cache folder resolves the issue.
On one occasion, I had "run out of licences" - that is, I activated Resolve on more than two systems but for whatever reason that third installation started ok anyways.

I kept finding online references of licensing issues with some artefacts at the top of the screen. I closed Resolve and re-opened it and (without me doing anything) it asked me to activate again.

Once activated the artefacts disappeared.