You cannot fly from Bangkok to Phuket if you are doing Sandbox.You need to fly direct to Phuket.Im sure a lot of people have been caught out via airlines and on line travel firms,that advise you can change at Bangkok.
Happened to me in November..all good now...looking at going again middle of January. Just read someone else stating that you can reapply for your Thai Pass..interesting..saves the expense of going to Phuket..
was going to return middle of January. But with the constant changing who knows...let's hope there is some good on January 4th..and I'm double jabbed..going for booster on the 6th January.
Same thing happened to me..my PCR came back positive. Go on the airlines website and rebook or cancel from there.if you went through an agent,then ask them to deal.with it.Im waiting to see what the Thai Government comes up with on the 4th January. The only other way in is via Phuket sandbox. Good luck..