My Premiere Pro is suddenly not working correctly-lagging, tools not working, selection not working

[BeastCharged100]

About a week ago, I bought and installed Premiere Pro 2020. It worked perfectly for the first video I edited. Today, when I tried to edit video in it, it was NOT working right. It was super laggy. I couldn't select things. I couldn't drag the playhead. Tons of things just didn't work. Here is what I KNOW is NOT the issue.

Drivers: I tried updating them and even trying two different graphics devices.

PC specs: They meet the requirements on your website. And also it worked perfectly a week ago.

Uninstalling it and reinstalling it: Didn't work.

Restarting computer: Didn't work.

I'll be really upset if I ended up paying for this and I can't get a solution. I need help as soon as possible.

EDIT: 

Actually, it seems to have fixed itself for some reason. After some experimenting, I ended up leaving everything the same. Works now for some reason. For people on this thread in the future, try these things:

1. Use OpenCl as your render instead of CUDA.

2. Don't insert webcam videos (seems random but seems to be what caused the problem).

3. Rollback to an earlier version of the software or your graphics drivers.

[Meg The Dog]

Try holding down the Alt key when launching and reset your preferences to default settings. It is possible they may have become corrupted. More info:

https://community.adobe.com/t5/premiere-pro/faq-how-to-reset-trash-preferences-in-premiere-pro/td-p/... 

Have you added any other software since it was working well?

Do you have sufficient drive space to work with your media and the application?

MtD

[BeastCharged100]

I tried resetting my preferences but it didn't work. I haven't added any new software since and and I have over 100 GB of space left. What should I do next?

[BeastCharged100]

Actually, it seems to have fixed itself for some reason. After some experimenting, I ended up leaving everything the same. Works now for some reason. For people on this thread in the future, try these things:

1. Use OpenCl as your render instead of CUDA.

2. Don't insert webcam videos (seems random but seems to be what caused the problem).

3. Rollback to an earlier version of the software or your graphics drivers.

[defaultc655to6pp6jp]

I'm having the exact same problem right now. I edited a video earlier today and it was working as it normally does, and now for some reason it's having these issues. How long did it take to go back to normal for you?