Ok.
So i would check ikev2.xmll file on the gw while 'vpn debug trunc ALL=5' is on. And you use ikev2.
Look under the relevant peer under authentication.
The type should be IPV4_ADDR usually (where at the screenshot it says KEY_ID)
Then at the data see the actual ID sent. And weather it's indeed 0.0.0.0 or not.
If it is 0.0.0.0 you have something to show to TAC to investigate, or just consider change to FQDN as mentioned.
If its other valid value. Then it means you don't send 0.0.0.0 as ID. And i would ask PAN side for the proof of ike packet coming with 0.0