So I recently recovered my Dad's old Blockchain.com wallet from 2016.  When I tried to send 1 BTC to Coinbase, the blockchain.com wallet decided to send 5.  Looking at the transaction id, it sent 1 BTC to coinbase, which i received as intended, but it sent 4 BTC to a completely different address.  Why on earth did this happen and how do I recover these 4 BTC?!  I reached out to Blockchain.com customer support but have not heard from them.