VA direct deposit froze USAA account

My VA was settled after 2 years and the backpay was 30k and then USAA called to ask what the funds were from and then froze my account and now I have no access for over 2 months. I asked why but was told it's under fraud investigation and that is all they can disclose at this time. What is happening and why is this happening? They can clearly see it was a direct deposit from the US Government. Called the VA and was given a number to call to see if the section for direct deposits could do anything and it took a week to even get a response and was told that since USAA accepted the deposit into the account that VA could not do anything.