I am trying to use my Yubikey to sign git commits. I was able to create a master key with three subkeys (authentication, signing and encryption).
After I created the subkeys I moved them to my new yubikey. So on the computer I created the keys everything works fine. Meaning that I am only able to sing commits (and files) if I insert my yubikey.
However, I exported the public key of my master key and imported it on antoher machine. Now on this other machine it shows that the subkeys are stored on the computer instead of my yubikey. Furthermore, I am able to sign commits and files without having to insert my yubikey.
Does anyone of you have an idea what I did wrong?