Tunnel monitoring showing down with paloalto firewall

Hello all,

I have site 2 site tunnel between paloalto and fortigate firewall.

On paloalto firewall i have enabled tunnel monitoring with fortigate but i can see on paloalto tunnel monitoring shows down.

i can see packet send on paloalto keep on increasing but packet received is 0.

no issue with monitoring range proxy ID but issue with all other proxy ID in same tunnel.

Anyone know how it works and what i may be missing.