These could be herpes lesions or they could be canker sores, either is possible.
Forget the VZV testing – most everyone has antibody to VZZ from chicken pox or chicken pox vaccine. It doesn’t mean anything in terms of the mouth sores.
If you were my patient, I would give you some PCR swabs to take home to swab these the moment they show up. You should ask your provider about that to get a very timely swab.
It would be unusual for intraoral HSV 1 not to respond to suppression so I’m a bit skeptical about these all being herpes but best to find out with PCR swabbin.