Have you put your issue with the import on the Navigraph forum? They’re always helpful and if they can reproduce they fix it immediately.
And the weather, P2ATC uses NOAA weather by default I believe, and the sim real weather is not exactly working. That’s why I changed to Unreal Weather - Live METAR Mod when using P2ATC, because it’s more accurate. But it’s metar based obviously, so when there are no station near you’re stuck with the latest weather (like oceanic crossing)