I am on a workation DTV and my Bangkok Bank account is in good standing.
I just came to their branch in CM to restore online access, and everything is fine and working, they didn't mind about my visa.
It's worth mentioning that I've had this account since 2019, opened with the help of an agent. Always on a tourist visa.
I am seeing a lot of posts here about account closures, so I can only guess that their policy is inconsistent - maybe due to different account opening years or branches / jurisdictions.
In Chiang Mai I had no problems.