[mzman]

Can someone test this please, using some app like Sensors Test or similar?
https://forums.androidcentral.com/e?...token=6-MkUrEe

If I suddenly expose the phone to bright sunlight, the proximity sensor says it's covered. Is it a hardware defect on my phone or a design problem with the M9?

Any data would be appreciated. A malfunctioning proximity sensor can cause annoying problems!

[N4Newbie]

Are you using a screen protector? If so, it is very likely the problem.

[mzman]

Are you using a screen protector? If so, it is very likely the problem.

I'm not - no case either

[davidtm]

Try the built-in hardware tests by entering *#*#3424#*#* into the phone dialer and see if you get the same result.

I've not noticed the same problem you describe.

[mzman]

I'll try that when it acts up. I wonder if this is a more general problem? Perhaps an instance of this issue:
https://productforums.google.com/for...us/oqh-V37hgDM

[mzman]

Try the built-in hardware tests by entering *#*#3424#*#* into the phone dialer and see if you get the same result.

I've not noticed the same problem you describe.

Have you found a fix? I've been rebooting fairly often, which seems to prevent the issue for a while.

[GSDer]

To check the proximity sensor operation without using a 3rd party app you can simply make a phone call, then hold the phone next to your face (at which point the screen should turn off) and then move it away from your face (and the screen should turn back on).

If this isn't working reliably reboot into Safe Mode and do the same test - this will eliminate interference from any 3rd party apps. If a problem still exists then a Factory Reset is in order - if that fails to correct the issue then you have a hardware problem.

As the earlier poster noted, it's very common to have a poorly aligned screen protector cause this kind of issue, but since you don't have that or a case the rest of the troubleshooting is necessary.