A few of routers were hard down because of a full disk usage that caused full CPU utilization & memory utilization as well.
Salt and dnf og files were not getting rotated. This was causing huge utilisation over a period on time for /var/log/salt and /var/log/dnf directories.
Once the disk space is fully utilised the SSR routers stoped working.
This issue is a known issue and upgrade of conductor to Version 6.2.9 will fix the issue.