Hi,
This might be caused by software conflicts after the downgrade. To help you eliminate the software conflicts, you can perform a clean boot. Refer to this article on how to perform a clean boot.
You can also try checking if the same issue will happen when you boot your PC in safe mode. Safe mode starts Windows in a basic state, using a limited set of files and drivers. It can help you troubleshoot problems on your PC.
Get back to us with the outcome so we can provide further assistance.