I'm not familiar with F5, but assuming there are multiple pools that are UP for the node, your reset is only check if at least 1 of them is up. Then it's resetting. You probably want to reset when there are NO pools down. If you want to be specific to the pool that triggered the alert, you may have to save the pool that triggered the alert in a custom property.
Maybe use this as your reset (to determine that none are down) ...
WHERE NodeId NOT IN (
SELECT NodeID
FROM F5_Device_V dv
JOIN F5_Pools p ON dv.NodeID = p.NodeID
WHERE dv.F5_Pools_AvailabilityState = 3
)
p.s. Corrected (Sorry... for some reason this website reverts to the old editor and it gives me fits.)