No rain in Minecraft 1.14?

I wanted to make some pictures in Minecraft. I thought with shader and rain you could make some beautiful pictures, but the command / weather rain is not running or it is indeed in the chat: "Set the weather to rain" but it does not change.

Does anyone know how I can fix this?

It does not rain in Table Mountains, deserts, savannas, the Nether and all final biomes.