Weather often does not get injected

1) I search for airports having weather with "RA" (rain)
2) I move to that airport
3) the weather has clouds, but no rain. This happens 90% of the time. I even click "Set WX", but it doesn't help.

Alternatively, I can sit at an airport, and search weather history for a date/time when it is raining, and then apply that weather, and there is no rain.

My conjecture is that if the metar for a particular station has "RA", it causes FSrealWX to plop a random arrangement of rain "areas" on the larger grid for that area, and the airport location itself may not actually coincide with one of those areas at the moment it injects the weather. Is this correct?

Please help me troubleshoot this.

I guess it's just normal. Once I fly around a little, I usually eventually encounter the rain, which is consistent with my conjecture above.