In addition to what has been said already, I just want to add that Fixedfloat IMMEDIATELY transferred the BTC I sent to their hot wallet, which means it was already added to their pool of money they use to draw funds to send to their customers.

If there were any legitimate concerns about money-laundering, etc, the practice is to either keep the sats frozen at the address they were sent to, or for them to be transferred to a dedicated cold-storage wallet.

This is proof positive that their intention was never AML in the first place. It's a ruse to steal funds, nothing more, nothing less.