What could have caused the rejection of a Soft Power Muay Thai visa application in Hanoi?

Question for people who have applied for Soft Power in Hanoi in the past 2 weeks. Have any of you had any issues with your application? My partner's Soft Power Muay Thai application was rejected last week even though he fits all the criteria, there is no visible issue on the application form... all 100% correct. The Muay Thai gym he chose has had a number of successful DTV applications via Hanoi. No rejections.

He was and still is in Hanoi, in case that question comes up.

I'm trying to figure out what went wrong.

Paperwork provided:

* Bank statements showing 500k on a Thai Bank account since early Feb (he has been in Thailand on an ED visa which expired on 15 March. Application submitted on 16th March). Bank statements started on 1/10/25 so technically not full 6 months. I realised just now. He stopped using that bank account in Feb when he had the full 500k on the account. I'm wondering if that was the problem.

* Muay Thai Gym, which is registered with Thai Sports Authority and has an ID card to prove it. Full documents from the gym including proof of payment. I checked and the payment was made from a different bank account than the bank statements provided. Again wondering if this could have been the problem.

They didn't ask for any further documents. It went from Pending approval 1 day after submission, to rejected 2 days after submission.

When we called the embassy in Hanoi they were helpful and said there was a problem with those specific documents (bank statements and Muay Thai Gym documents) but they couldn't give any further information as to what was the problem with them exactly.

So I'm reaching out to see if anyone else has encountered a problem recently, that could be caused by a change in policy that I'm not aware of. Or if anyone can give me some insight and help figure out exactly what went wrong.