Why did immigration request a bank book update without wanting the bank letter to show amounts in bahts for a non-O visa application?

IV come in on 30 days entry, now moving to a 90 day non o based on being married to a Thai. All the paperwork has gone in , on putting in into jomtien immigration. I pointed out that my thai account is in sterling and that the account has never been below 2 million. The bank letter confirmed the account transfering the amount to bahts. The money in the account was transferred from my UK account 4 years ago and not used that much for withdrawal but as it say never went under 2 million. This is the same account I used for a non o visa based on being over 50 for years. As I was stuck in the UK my retirement visa past renewal date, so as I was starting from scratch I went for the visa based on marriage. Today for some unknown reason after a week they asked me for a bank book update but did not want the bank letter to show it in bahts. Doesn't seem to make much sense , has any one have any idea what might be going on.