Sw200-1 issues

Anyone have any experience with the sw200-1?

A recently new watch I have with one was running very nicely at about 2 spd

I went to wear it one day and saw it it had stopped which was weird as it should have had a full wind

Gave it a couple of winds but it wouldn’t run. Giving it a shake made it run for about 5 seconds

Came back to it a day or so later and it was running without any further external influence but was running faster at about 15spd

It has since stopped again, won’t wind and a shake will only run it for a few seconds

Anyone have any ideas what might be wrong with it?

I guess it needs to go back for a warranty fix but if it’s a cheap fix then I may not bother

Cheers

Magnetised?