There could be a lot of reasons for this. First up I would recommend checking out your browser. Try another browser like Chrome or Edge to see if they work. If they do, it is likely your current browser and you can follow this to fix it: How to fix/turn on your browser's hardware acceleration
Otherwise, it is likely a world size issue, and you can go through this: World Size Check
If neither of those work, could you press f12 → console and screenshot any red errors?