I have ben turning off 3D touch recently, and things seem a little better on my iPhone, 3D touch applies to iPhones 6S and above. It is meant to add another dimension or quick menu to the press of the button, but for me and others, it seems to appear when unwanted, especially when opening the camera quickly.
So if not using it, then turn it off.
And here is how

Goto Settings

Then General


Then Accessibility


Then Turn off 3D Touch