Why is Bitcoin blocked in IBKR

I’m with IBKR UK. I noticed that bitcoin related funds e.g. GBTC and IBIT are blocked.

Does anyone know the reason for the block? I know that there are other ways to buy BTC, but I was wondering why/how these funds are blocked and who is blocking (IBKR?, UK?, CH?)?

Is it blocked? Does not look blocked for me. You just need to request permission to trade complex/leveraged products and you should be good to go.

e.g IBIT: “Trading Restricted: Clients from your country cannot open positions in crypto-related products.”