I’m not on a DTV but neither am I on any kind of visa, long term or otherwise. Had my Bangkok Bank account for a very long time, like over 10 years. Updated my info in Bangkok this May, with some difficulties, but got it done eventually (not at the branch I opened the account at, which was the initial problem) so they completed the profile photo scan, updated the app on my new phone etc.
I had to go and get a replacement passbook, which meant going to the original branch in Chiang Rai. That was fine, but when I also needed a replacement bank card, for some reason the system wouldn’t unlock the card (I’d locked it on the app when I lost it). No problem,they said, we’ll just do a new card application. That’s when there was a problem because of my visa, or lack thereof.
Luckily I had my marriage certificate (both คร.2 and 3) as I had wondered if those might help, given that marriage to a Thai national is one of the reasons Bangkok Bank give for allowing a foreigner to have an account.
So, another 57 signatures on pieces of paper later, I had my new card but if I hadn’t had proof of marriage to a Thai national with me, I think there would’ve been a problem. One that may well have resulted in the closure, or suspension, of my account.
That was a few days ago now and the account, and app, are all working fine.
So yes, even accounts opened over a decade ago, like mine, will be subject to scrutiny if you need anything updating at a branch. If your current credentials don’t match their current policy enforcement, then you might have a problem.