Nexus 5 : after a repair , my bluetooth is now bad

Hi,

I had my nexus 5 power button repaired,

Now my Bluetooth is bad. I have no connection. If I whant it to work, I have to press the front and the back of my phone with my fingers on the side of the power button. near the sim cart slot.

Is there a antenna connection there?

Should I open it and screw harder?

... and no the repair shop is not offering a good service...