Demo Start AR not working in Android Chrome but ok in Samsung browser

I installed google ar service to my Samsung Galaxy S20 FE 5G phone(Android 11). The AR portion of three.js webXR demo example shows nothing after clicking “Start AR” button in Android Chrome (version 87.0.4280.141) . VR demo example works in Chrome. But the “Start AR” and “Enter VR” functions both work fine in Samsung browser (version 16.0.2.19) in the same phone.

What is the problem? How to fix it ?

This is the AR example link:
https://threejs.org/examples/?q=webxr#webxr_ar_cones

The Samsung Galaxy S20 FE 5G is a new phone. The example link does not work in Android Chrome in the beginning. But after I invoke the Android developer tool in the phone and enable its usb debugger, the three.js AR example starts to work. It works even I turn off Android USB debugger.
However I did see an error message in the console

THREE.WebGLRenderer: Can’t change size while VR device is presenting.
WebGLRender.setSize @three.moudle.js:25726
onWindowResize @webxr_ar_cones.html:80

This is weird and makes me worry about what if end users who never use Android developer and USB debugger option.