I think David is correct for now but others have been caught out, can depend what you do from the account and whether using app or online and your credit/debit card use in Thailand over an extended period of time.
Keep a UK address and change account details before you get here, it's not a guarantee of success and obvious account activity sourced from Thailand is a "giveaway" so use Wise for money transfers and don't buy or withdraw money using your banks debit or credit cards.
Surely it is not "always" readily available to meet immigration office requirements (not drop below 400k and be in the account 3 months before and 2 months after?)