Availability Graph Calculation

Hello everyone I am trying to get device Availability for the last day 24h with Availability map but the AV graph doesn’t show the outages and the AV% value is not correct if it depends on Ping or SNMP because the device was down for long time. Attached Images to see the difference .


I need help to understand how the Availability works in LibreNMS and how to get the value that i need.