Hmm, that's odd.

I'm using the correct P3Dv2 version but, as stated, still have simconnect issues, the symptoms of which are exactly as you describe. Said issues are immediately fixed upon executing the simconnect package.

Some folks have claimed to successfully use the -300 and freighter versions in P3D, even though CS has only released them for FSX. I would have figured that this would mean the base model would work as well. I can't attest to this since I only have the base model.

Have you tried following the proper activation procedures (running the installer as administrator, using manual offline activation, etc.)? Have you deleted the Captain Sim registry keys?

Also, I assume that you had FSX installed at some point? I wonder if something is still pointing the aircraft files to your FSX installation, whether you've deleted it or not...