Good morning everyone

I have many RB-411 and RB711 devices on the network.
In the last months it has been happening that this message appears when the automatic backups are done by script:

error creating backup file: could not read all configuration files

We already know that it is corrected, regenerating the SSH Key: with the commands:

ip ssh regenerate-host-key
system reboot

The query I want to do and what I want to investigate is. Why is this happening and only with that device model?

Please if anyone has any information on this that they can share.

Thank you all