Why doesn't the weather change in Minecraft?

I'm currently playing in a single player world with Forge in 1.12.2 and using a few mods (Pixelmon, Just enough items, Custom Npc, Optifine, Varied communities and any mod with a minimap Xaeros Minimap or something like that was the name of the mod) and the weather doesn't change. I've already gone into a creative world to use / toggledownfall, but it doesn't work either, the weather just doesn't change. After I entered the command it even says: "Precipitation changed" but it doesn't start to rain. I've been playing Minecraft for so long now and I've never had it before and don't know how to get it. Can it also be a graphics setting? If you're wondering why I want it to rain, with the Pixelmon mod some Pokemon only spawn when it rains or thunderstorms and without these two things, I don't really want to continue playing. Hope you can help me.

Rejoin and try again

You can do it with

/ weather clear | rain | thunder

If it still doesn't work, then it's due to some mod

And if it were due to the graphics settings, then it would rain in Minecraft, but you won't see it, but the Pokemons that only spawn when it rains can then spawn

I've already tried / weather rain, but it didn't work either. I'll try to make a new world completely without mods to see if it's a mod.

Found the problem. It was up to Optifine. In the settings of Optifine there's the item "Weather" and it was turned off. I wonder how I managed to display it without noticing xD Thanks for your answer ^^

XD

With pleasure

Try / gamerule DoDaylighcycle true

Should then go again.

I've already solved the problem, don't know if I can somehow delete the question. It was due to Optifine hiring. Still thanks ^^