Do I need to maintain a bank balance of over 400,000 THB for a longer time for my extension under marriage?

Hi my wife has just had a call from Udon Immigration, I was their in January to renew my extension to stay under marriage showed my bank statement over the 400000 in my account now have to show again, is this new? never had to do this before,does mean we have to keep over 400000 for longer time now, info would be great.