<p>It sounds like you’re having some graphics issues with your new AMD RX 6400. The weather clipping and missing shadows could be related to driver settings or game compatibility. Since you’ve already tried rolling back the driver and adjusting settings, I’d suggest checking if there are any updates for both your graphics card and The Sims 3. Sometimes, running the game in compatibility mode or adjusting the graphics settings within the game itself can help fix these issues.</p><p>If you’re looking for more help with how to know if your TM SIM is registered, you can Read more about it on the TM app or website for easy checks.</p>