Inserting your HTC phone in a car kit or selfie stick will apply some pressure to the lower sides of the phone and may be mistaken to be a squeeze gesture.
If the phone remains in this squeezed position for over 5 seconds, it will not trigger
Edge Sense.
If you want to ensure your phone won't trigger Edge Sense, you can turn the feature off whenever you need to use a car kit or selfie stick.
Just swipe down from the top of the screen with two fingers to open Quick Settings, and then tap Edge Sense to turn it off.
Why won't
Edge Sense squeeze gestures work when the phone is facing down?
When your phone is facing down and the screen is off, the phone will not allow you to use
Edge Sense.
This is to prevent you from accidentally triggering the squeeze gestures when you lift your phone from a flat surface while it's facing down.
If you need to hold the phone facing down to capture something high above you—such as the sky or high objects—but squeezing won't take the shot, try tilting the phone's angle to about 45 degrees and then squeeze the lower sides of your phone.
Why won't Edge Sense squeeze gestures work when the screen is off?
It is possible the proximity sensor has been blocked—for instance, by the screen protector or case. Please make sure the proximity sensor is not covered.
When the screen is off and the proximity sensor is blocked, the phone will not allow you to use Edge Sense. This is to prevent you from accidentally triggering the squeeze gestures when you grab the phone out of your bag or you're holding it close to your ear during a call.