I found a note here: https://www.openssh.com/txt/release-8.2; ssh-rsa key (2048-bit) using weak hashing algorithm; Which pointed me to this: https://www.ssh-audit.com/hardening_guides.html
I followed this guide to secure my ssh server, after that, there were no more problems. You should also move to modern Ciphers if ssh-rsa is the problem.
Do you have console access?