Premier pro crash every time

Hello,

I got a new computer 4 months ago (see composition below) to use premier pro. Everything was working fine until Monday, my premier pro started lagging, rowing. Pre-visualization was lagging also, the time-line was displaying in red just by using 2 images of 5 seconds each, and my project was systematically crashing. As I said, everything has been working fine before monday.

I've tried to solve the problem 1,000 different ways, and I can't tell if it's a computer problem or a premier pro problem.

Here's a list of what I've done:

- I uninstalled premier

- I deleted the media cache

- increased the amount of ram allocated to premier pro

- performed the latest updates

- I've run a RAM diagnostic on my PC, which shows no anomalies

- I've checked my CPU temperature, and it doesn't overheat when I use premier pro. In fact, I don't get the impression that my processor is overexploited. It doesn't usually exceed 60% utilization.

- I've done a performance test which tells me that my CPU's performance is below expectations.

My computer: 
- Type: Yoga slim 6

- Processor 12th Gen Intel(R) Core(TM) i7-1260P 2.10 GHz
- RAM installed 16.0 GB (15.7 GB usable)
- System type 64-bit operating system, x64 processor

With a 30-second video, my time line is red

If you have any idea what's going on.

Thank you.