The Bug
Rain and Snow can go through froglights
Reproduce
Create a roof made out of froglights
Do /weather rain
Observed Result
The rain/snow went through the froglights
Expected Result
The rain/snow wouldn't go through the froglights
Rain and Snow can go through froglights
Create a roof made out of froglights
Do /weather rain
The rain/snow went through the froglights
The rain/snow wouldn't go through the froglights
I can also confirm this behavior. As an additional note that I feel is worth mentioning, the precipitation that appears below these blocks is "ghost precipitation". Basically, it appears as if it's raining/snowing, but if you were to attempt to throw a riptide trident whilst standing under these blocks, you'll notice that you will be unable to do so. This ticket closely relates to MC-205442 and MC-214901.