Can you open a Thai bank account with a DTV visa?

Generally no although on a very few occasions it has been done successfully. You need a non tourist type visa to open a bank account at the moment

Having a DTV does not automatically make you eligible for opening a bank account.

May get a agent who can help, but many of them are also unable to help you after the banks tightened their rules recently.

Theoretically, it's possible, but it's not enough to just walk into the first bank you see and think you'll get an account there. You'll probably have to walk into 30, 40, or 50 banks and try consistently. I'm sure then you'll get a bank account. There are a few success stories, and as far as I can remember, they included among other things a certificate of residence. I would collect everything from Thai driver's licenses to your health insurance. They just want to see as many official documents as possible to make sure you are legal

Look through the group. This is a question asked quite frequently.

It seems your chances are getting pretty low now, based on the last few comments. Only a small amount managed to do so in the past but rules are getting stricter and stricter.