Why is my USD unavailable on Binance?

I've been encountering an issue lately with my funds on Binance. Could you possibly help me understand why my USD is not available for withdrawal or trading? I've checked my account balance, and the funds are indeed reflected there, but whenever I try to initiate a transaction, I'm prompted with a message stating that the funds are unavailable. I've ensured that there are no pending orders or ongoing transactions that could be causing this. Could it be a technical glitch, or is there some other reason behind this? I'd appreciate any insight you could provide to resolve this matter.