I don't know if this is a bug, but it doesn't make any sense at all. If you place sponge block while it's raining the sponge won't get wet. That doesn't make any sense since you can get it wet in the water but why can't you while it's raining. I don't get it.
-ZombieHD01
The issue is invalid.
That's because this site is not for feature requests, go to reddit (minecraft suggestions) for suggestions.