Changing the dimension type of the overworld to any other dimension type (such as a custom one), will not allow weather changes to take effect until the server is restarted (in multiplayer logging out and back in doesn't change the weather).

Steps to reproduce:

1. Create a data pack with the file data/minecraft/dimension/overworld.json set to

   {
       "type": "minecraft:the_nether",
       "generator": {
           "type": "minecraft:noise",
           "settings": "minecraft:overworld",
           "biome_source": {
               "type": "minecraft:multi_noise",
               "preset": "minecraft:overworld"
           }
       }
   }

   or download and install the attached data pack MC-264273.zip

2. Enter the world and use /weather to change the weather
3. Observe no change
4. Close the world (in multiplayer, shut down the server)
5. Enter the world once again
6. Notice how the weather has now changed

Expected result:
Weather would just change on the fly, like with dimension type set to minecraft:overworld.

Actual result:
Weather only changes between server-end startups.