Only had my Zenfone 8 for a few weeks but recently noticed a click noise a little while (15-30 seconds) after unlocking. It sounds identical to the noise made by the camera when switching between front and rear facing cameras. I don't recall it happening when I first received the phone, seems since the last update. Anybody else experiencing this? I don't use face unlock either.
I raised a case with Asus support who got me to reset my phone - problem went away, until I enabled the smart screen option. Now I'm fairly sure I turned this off prior to the reset as it made sense that it'd be using the camera, however the problem didn't go away at the time, so the reset may have cleared something. Thought I'd let anybody else know that has experienced the problem. Extending the display timeout would also reduce the frequency of the click as it only seems to occur as the phone is checking if you're looking at it.