I did a system restore on my Dell Laptop running Windows 10. Then I downloaded bitwarden on to the computer. The first time I logged in to bitwarden it only required my master password. I logged out of bitwarden and then logged in again and this time it required me to squeeze my Yubikey. Subsequent logins all required me to use the Yubikey. Suggest this is a bug.
Hi @robwet - welcome!
If you did a full restore on your machine, you might have actually unlocked your previous session. That won’t trigger 2FA,if so. If you were prompted after logging out of Bitwarden, then that is expected behaviour as well.