In container key search starts with container, then server, then local
Since container is OpenSSH 8.9 and local/server is lower than 8.9, this causes problems due to the mismatch.
This was isolated on dev laptop where local version is 8.6, Alta version is 8.7, and container version is 8.9 whereas personal laptop has local version 8.9.
Reproducible versioning: https://gist.github.com/syoh/dc7b8a2beb57f98e49b92eddc0da2967