how do I fix ssh?

[Jim]

Somehow I screwed up ssh on my Raspberry pi that runs ubuntu 20.04 and 
my desktop that runs Kubuntu 22.04.  When I try to log into one from the 
other, I get an error message.

Logging into the desktop from the Pi gives me this error: Load key 
"/home/pi/.ssh/id_rsa.pub": invalid format and I'm prompted for a password.

In both of them I deleted id_rsa and id_rsa.pub.  Then I tried 
ssh-keygen, ssh-copy-id, then tried to log  in like ssh-copy-id said to 
(ssh username at ip.address.of.other.machine).

  When I tried to log into the Pi from the desktop, the error I get is 
Load key "/home/desktop.user/.ssh/id_rsa.pub": error in libcrypto

When  try to log into the desktop from the Pi, the error message I get 
is Load key "/home/pi.user/.ssh/id_rsa.pub": invalid format

In both cases I'm prompted for a password and I'm able to log in.

The permissions of the files in the .ssh directory on both machines is 
the same

-rw------- 1 delboy delboy  564 Oct 21 22:47 authorized_keys
-rwxr--r-- 1 delboy delboy  122 Oct 21 18:27 config
-rw------- 1 delboy delboy 2602 Oct 21 22:43 id_rsa
-rwx------ 1 delboy delboy  566 Oct 21 22:43 id_rsa.pub
-rw------- 1 delboy delboy  364 Oct 21 22:44 known_hosts

In both machines, how can I reset ssh to the state it was in when I 
first installed the OS on each machine?

Thanks