How to troubleshoot and fix Hall sensor: not sleep on lid close

Hi, my Pixelbook is not sleeping on lid close. I am pretty sure that the battery mode is set correctly in the OS.

I very much suspect it to be the Hall effect sensor hardware failure. Because when I hold a magnet(like AirPod case, iPad cover, etc.) close to the right hand side of the keyboard, where the Hall effect sensor locates, the Pixelbook is not sleeping nor turning off the screen. If I do the same test on other PC/Macs, they will turn off the screen immediately.

I wonder if anybody has encountered the same issue as mine? Or has anyone got experience with troubleshooting and fixing the Hall effect sensor on notebooks?

Thanks in advance!