ssl inspection PKI issue - inbound policy (protecting a server)

hi all,

so i'm trying to solve this issue for the last few days.

first i have imported my server certificate onto my fortigate unit as local certificate (public+private).

second i activated ssl-inspection profile with the option "protecting a server" which i understand means replace certificate instad of resign

and last i have activated that profile on my inbound traffic (VIP->SERVER HTTPS).

now when someone try to access that certifiace it fails most of the time beacuse it seems the PKI chain is broken.

i also installed the subordiante CA (go daddy g2 CA) on my unit as external ca with the same results.