Personally I would try a different branch of the bank - they all seem to have their own rules. I've never heard of Immigration having to certify your passport before.
The letter from your wife stems from a few years ago when people were separating or divorcing and still using old marriage certificates as a convenient way to enter the country. Some embassies ( the one in Australia for instance) used to insist on it. It just has to say (in Thai) “Fred Smiff, passport number FS
*****
67 is still my husband, please grant him a visa” and be signed by her.
it doesn’t need to be shown at your 90 day reporting, but for an annual extension, yes, it needs to be there and “cooking” for at least 2 months prior to your extension application.