Brian was dwindled out of A LOT of money when Chopped really took off, by his old accountant and his former business partner in the old TRX gym (these two people are married couple), it was kept under wraps to protect the reputation of Brian, as he didn't want such a massive scandal so early in his career, to make him look naive, not missing so much money.
But that's all true. Add the pressures effects of covid on his businesses. Must have finally forced him to partner up with Timmy. Brian may also desperate to keep himself in the big boy league, he's allowing little scam boys to eat at his table from time to time