accessing a fedora box (latest fedora 35) from Windows using PuTTY/WinSCP only possible with userid/password

[Walter H.]

Hello,

can someone please give me a hint, where to look for the following 
problem ...

I have several Linux VMs (all except this one are CentOS), and I took 
/root/.ssh/authorized_keys from one of them
and copied it onto this Fedora box;

accessing from my Jump-VM also directly using SSH from Win10 works fine 
using the private key,
but from when using PuTTY/WinSCP I get: "Server refused our key."
(all other Linux-VMs use the same authorized_keys and can be accessed 
using PuTTY/WinSCP with this private key)

is there something I must change on the side of the Fedora box or 
something I have to change in PuTTY/WinSCP?
(I'm using the latest releases of PuTTY/WinSCP)

Thanks,
Walter