Passkey keeps timing out or cancelling during setup – what can I do?

I would like to set up a passkey to make logging in more convenient, but it keeps failing. My network connection is normal, and I don't have a VPN turned on. After entering the verification code, I don't do anything—I just wait for the passkey to be sent. But either it times out or says it's been cancelled, even though I haven't done anything. I've also tried using mobile data, but the same thing happens. I hope you can help me. Thank you.