FIDO U2F Safari

Hello everyone,

Hope someone can help me out here.
I have vaultwarden installed on a Synology DS in Docker. I am using a yubikey for 2FA. With OTP it works just fine everywhere.
When I want to use FIDO U2F instead it depends on the browser I am using. Firefox, and Edge work just fine. However it doesnt work on Safari on my mac. Vaultwarden tells me that the browser is not supported.
I tired the FIDO Demo website by yubikey and that works perfectly with safari.
Have I missed something setting it up or is that a bug or some other reason?

What can I do?

Thanks