XPS 13 Plus 9320, capacitive touch key buttons not working

I got the first XPS 13 Plus 9320 in late June.

After several weeks, the first row of the keyboard (the capacitive touch key buttons) stopped to work. I tried to touch that area, and it was hot. Also I lost the left side speaker only the right side speaker worked when I played the music.

The local Dell shop in China finally agreed to replace the laptop for me. And I received a new laptop this Monday. Everything looked good until the laptop rebooted by itself suddenly. The same problem occurred. The capacitive touch key buttons overheat and malfunctions. The left side speaker has no output.

I do like this laptop. However, the two laptops showed the same problem, which is really frustrating.

Possible to save the issue? Thanks.