Inspiron 14 5401, shuts down during Zoom call

Hi, May someone please help me? I bought this laptop last December 4, 2020.

The first time I used it, whenever I play an audio during the Zoom class, the other party couldn't almost hear it. The sound is very low.

The 2nd week, during the Zoom classes, the camera randomly shuts off. I could still see the camera light but the whole screen is black. The other party could still hear and see me. They could even see the screen that I was sharing but I couldn't see them. No matter what I pressed, the screen is still color black. And then 5 mins. later, it will open again.

I am so stressed because of this laptop. I always buy DELL Laptop, but I won't buy it again in the future. The DELL customer support is so hard to reach. They always passed me to another one.