Michaeltate

I purchased bitcoin and sold it later for some profit. Instead of selling it back for GBP, I sold it for USDT, a stable cryptocurrency coin. I understand I have to pay for the capital gain tax for the profit in GBP value at the time I sold the bitcoin. Afterwards, I sent the USDT I got from this bitcoin-USDT transaction to my brother. By HMRC’s definition, it is a disposal of asset. Do I have to pay for another CGT for this transfer even the USDT I hold hasn’t gone up in value in GBP term?