Ssh connection. Deprecated keys

I tried to connect to a server with ip xxx.150. During connection the server redirects me to ip xxx.151 or ip xxx.152. Each has it's own ED25519 and ECDSA keys. so i saved two keys from xxx.151 and two keys from xxx.152 to my known_hosts file. If the server redirects me for example to xxx.151, ssh said that other keys (belonging to xxx.152) are deprecated and deletes them.Here is the part of ssh verbose mode:

debug3: hostkeys_find: found ssh-ed25519 key at /home/nazar_s/.ssh/known_hosts:1debug3: hostkeys_find: found ecdsa-sha2-nistp256 key at /home/nazar_s/.ssh/known_hosts:2debug3: hostkeys_find: deprecated ssh-ed25519 key at /home/nazar_s/.ssh/known_hosts:3debug3: hostkeys_find: deprecated ecdsa-sha2-nistp256 key at /home/nazar_s/.ssh/known_hosts:4...debug3: client_input_hostkeys: 3 server keys: 1 new, 1 retained, 1 incomplete match. 2 to remove

What can I do that ssh doesn't delete these keys?

Thanks,Nazar