Server's Host Key is Unknown - Hashes do not match.

Hi.

I'm trying to setup an SFTP connection between Filezilla client (Windows) and a Debian server.

When I try to establish the connection, Filezilla says:

"Server's Host Key is Unknown"

Details:

Server algorithm: ssh-ed25519 256
Fingerprints: SHA256 and MD5.

I know for sure the server is the right one (it's a home lab).

If I go to the server and issue an

sha256sum /etc/ssh/<whatever file>,

it doesn't give me the same checksum result.

What am I doing wrong?
How can I know which key is Filezilla checking?

Thanks!