Rain doesn't produce any sound on water., try going to an ocean when raining.
Lighting, on all versions, sound is cut too early breaking the ambient. Normally there continues a little bass for some seconds, there are other lightnings that just hit and stop sound.
Environment
Music and sounds 100% speakers and sounds work fine in my computer
Lighting doesn't only glitch sounds when to many at the same time. Check the issue again about lightnings: toggle storm and listen to them. They go well 60% of the time but sometimes sound is just cut. I mean all is good but some of lightnings sound as if you get the audio and click the stop button.
-it is supposed to all server hear one lighting?