It is always thunderstorming in lush caves biome

When I am exploring the lush caves I always hear thunder, and I do /weather clear, but 30 seconds later I hear more thunder... This is annoying as I have to frequently do /weather.

How to reproduce:
1. Create a singleplayer world in 21w10a
2. Make it single biome: lush caves
3: wait for a few minutes
4: see how it starts thunderstorming a lot?