Not enough info to say. Need a lot more details about your setup.
It's perfectly normal for mobile IPsec not to have a remote network setup (in P1 or P2) since the P1 peer could be anyone, it determines keys by identifier and so on. And P2 remote is setup dynamically using the setting from the mobile clients tab.
Check your setup against the documentation and look for what you have wrong. Coming from a version as old as you had, it switched from racoon to strongSwan so odds are high that whatever you had setup before probably wasn't 100% right.
If your clients support it, you should move up to an IKEv2 setup.