It is a "Non-O visa", which is based on retirement, marriage but there is per se no "retirement visa" as well as there is no "marriage visa." My point was that the bank did not accept my non-O visa as they mistakenly believed that it should say "retirement visa" on the form from immigration I presented.
Try the bank account first. Again, the requirements vary from bank to bank. A few years ago when I opened my account, I had two different branches of SCB tell me two completely different things. One was not even willing to accept the Non-O Visa as they wanted specifically a “marriage” or “retirement” visa (which does not even exist). It is a lot of legwork but good luck!
A few years ago (before Non-O) visa I visited Thailand about 8 times within a year but every time it was only for a few days and immigration did not care. Your travel pattern looks inconspicuous so I would not worry.