Raintank Private Probe Issues

I have installed raintank private probe on a number of Linux boxes running centOS. 6 out of 8 probes are working perfectly however 2 of our probes seem like they are not sending pings to the requested endpoints.

The probe is online and checks into the dashboard but again no ping stats are available.

I have run tcp dumps from the linux box’s in question but cannot see any ICMP requests for any endpoints.

Firewall rules for HTTPS and ICMP are allowed outbound so no issue there.

Has anyone experienced the same?

Also is there a file installed that holds endpoint data?