Silent-Switch gets Triggered by applying pressure to the fron surface

Hi Guys,

my moms iphone 5 first got a new frond display assembly (worked pretty good) and later on a new battery.

One problem remained, there was a dent in the rear case preventing the screen from fully embedding into the device case. I wanted to fix it and tried to softly hammer out the corner. Now the case adhesive broke, as can be seen in the attached foto, at the righthand sided upper antenna-band connection.

Well the screen now can be fully embedded again (dou), its not looking nicely (any idea for fixes) and, most importantly, a new problem arose:

As soon as the front display assembly is fully embedded in the casing as it should, the silent/ringer-switch stops working and the software mechanism gets triggered by applying pressure at the display (sometimes the home-button presses, sometimes just touching the upper parts of the screen, like the back button). When i release the screen a bit again, the switch goes back to normal function without any problems. Any ideas where this probably short circuit or something could come from, what could trigger this and how to prevent it for future use?

Thank you so much :)