It's normal for these banks to verify the deposits and transfers. But it will be odd if the amount isn't that much and that's only a payment for something that you've purchased online. Based on your story, it looks like you have transferred a huge amount that triggered the bank to make that call and have some follow-up for another KYC. And that is true that with Bitcoin, this won't happen if you're going to send a payment to another wallet but it can also happen on exchanges if you deposit amounts that are out of your limits.
I didn't write this in my reply above but I know that is goes without saying that P2P trades are just seen by the banks as random transfers from one person's account to another, and comes with extra risk especially if they are transfers between international banks.
Domestic transfers and wires from reputable companies usually don't trigger this sort of investigation because in this case the banks can find all the info that they need.