My Minecraft keeps switching to the beta version

For the past two days, I've been experiencing this issue where every morning when I open the game, it suddenly defaults to the beta version. I've tried everything, from clearing the cache to uninstalling the game, and everything would return to normal. However, this morning, when I opened it, it defaulted to the beta version again. I'm feeling quite frustrated with this issue because my map and all the buildings I've built get deleted whenever I uninstall the game