Daily activity failure

morning peeps, I've got a M2 and recently it's not been recording any daily activity. It stopped recording last Wednesday morning, started again partway through Sunday evening, stopped again Mon & Tues this week but then started again this morning.

I've tried resyncing it to my flow app, restarting it, switching it off & on, updated the app, turned off & on Bluetooth & airplane modes, deleted & reinstalled the app, removed the watch from my phone & repaired it again, and done a full factory reset on the watch.

It was a bit low on battery but has been charged & that didn't make any difference.

It's recording sleep, heartbeat, breathing all fine but not daily activity & steps.

Anyone any ideas on anything else I can try, or of what might be up with it. The Polar help bot wasn't very helpful and I can't see a way to talk to a human on the site.

Apart from fitness, it's also tied into my health insurance so need to get it sorted soon.

Thanks