Describe the bug
If it is raining on Lantea, it cannot be turned off by doing /weather set clear, or by sleeping

To Reproduce
In the Overworld, do /weather set rain
Go through a stargate to Lantea
Use either method (/weather set clear or sleep at night) to clear the weather condition
Find out that you cannot

Not a bug on my side, this is Mojang's fault and it's a thing they fixed in one of the newer versions.