He explained it already. After your first flight, Live Weather stops working. The only way to get it working again is to restart the sim.
A lot of us are having this issue and have been since Day 1. There’s a workaround at the link below, but requires some steps be taken to “initialize” a baseline default weather and then to manually select Live Weather after we’ve loaded in every single flight. And this workaround gives us issues as well. Our takeoff and landing runways will be based on the default clear, 29.92, 225/5 weather vs actual conditions.
We shouldn’t have to do this. It should just work.