Hello Thanks for reaching out to Microsoft Q and A platform. So, the maximum threshold need to be set for data Path Availability is 100, anything which is going less than 100 you must get the alert. Indicating the Load Balancer is Un Available. Could you please set the Threshold to 100 and when the probes fail and goes down, your availability would reach less than 100% and throw you an alert.
Regards, Priya Kumar