Hey guys, I need some advice on a dual passport issue.

I have Israeli and French passports. Been in Thailand 2 years on a Non-B visa with the Israeli one, now switching to a student visa. The visa office asked me to re-enter with my French passport.

Problem: my flights are already booked like this:

-Chiang Mai → BKK → Vietnam (Israeli)

-Vietnam → BKK (French)

-BKK → Chiang Mai (Israeli) (booked this one long ago thats why its on israeli)

Goal is to enter Thailand on the French passport, but the flights are mixed. Did I mess up?

Since my tickets from Vietnam in on my french one ill need to enter Vietnam with my french one too isnt it?

Iam in UK , I have got previous a 6month visa twice and also a 2 year visa for my thai girlfriend.( son has dule passport )

Question is can I simply just renew it instead of all the paperwork each time.

Thanks in advance any help or advice.