I think somewhere I saw a user to create a topic about them holding his funds for 7 days and it was a while ago. I too do not use blockchain.com wallet but it seem this is a regular procedure for them to prevent fraud I guess.
If you can see the TXID in your trading account, check it and see if the funds went to the right address (the receiving address you have in your non-custodial wallet). If they did and they're still there, it can be glitch and in that case, I would suggest restoring your wallet inside the blockchain mobile app and see if anything shows there.
I think it's swapping from one type of account to another type like in Binance we see spot trading and leverage trading. In this case there will be no Tx.
I will contact support and hopefully get them back but what if they don't? Do I contact my bank?
I am not sure if the bank can help but surely you need to contact the support. Something was wrong with their system.