Since the latest update 1.18.12 rain and thunderstorms are almost constant on our Bedrock realm. Rain will not clear if you sleep through the night. It will not clear unless you log off the game and relog back in. Thunderstorms are almost a daily occurrence (similar to creative). This started in the previous update to 1.18.12 but is now more frequent since 1.18.12.

To replicate simply log onto any Bedrock realm for a series of MC days and you will notice the frequency of both rain and thunderstorms is higher than normal. When it rains, you can wait until night, sleep through the night and that rain will continue for multiple MC days. If you log out and back in, the rain will have stopped.