SLAs and PING Graphs empty


I am having issues with the SLAs graph displaying on my librenms.
I have added the $config[‘enable_sla’] = 1; in config.php and Tab shows up on the webUI.
All IP SLAs I set on my router show up, however all graphs are blank, There are no data being pulled to librenms and all graph shows -nanms.
Same thing is happening to the PING feature (also shows correctly on WebUI but no data).

Note all other graphs such as CPU, Network grah etc show correctly. Issue is only with SLAs and PING.

Do you have any idea where should I start looking ?

Run poller.php debug and pastebin the output. You can look at the output from the SLA module to see if anything sticks out at you.

Thank you for the quick reply.

I ran command :
./poller.php -h IPADDRESS -d

The only errors i see for this IPs are:
ERROR: Unable to connect to rrdcached: Permission denied

Note that health and port graph are displaying correctly.

I have also followed this thread but everything on my config is correct.