Hi there Kixyyyy

Well have you configured your bios yet?You said you swapped your motherboard and cpu so every time with a new motherboard the bios will be set on default and your boot order will be set out....I know this sounds stupid but sometimes resetting your bios helps!
Do you still have your old windows installed on your drive? If you still have your old windows installed on your drive it may be that its causing your windows to run slow because it has a system restore point to Windows Home(Old windows)...so basically you have 2 windows installed...I MAY BE WRONG.
Another thing you can try is...is to update your CPU driver and Mobo driver if you can...that will help or just to reset your PC again...make sure you have the newer version of windows installed(1909) and that the updates is updated.