Lock button won't work when wifi ground screw/back is placed

I opened up my iphone 4 because I was Having proximity issues so wanted t colour the glass which I did to no luck. I'm quite experienced with disassembly but this issue has just confused me.

My problem is that the lock button does work it definetly works it's new and when wifi antenna and screw are not placed the lock button works but as soon as I screw the plate in or put back on the lock button stops working. Now the proximity cable has a little tear on it so I used electric tape to make sure that's not the problem I suspect the lock button is shorting to ground somewhere that's why it's not working but I'm not sure it's a theory. The lock button not working when wifi antenna is screwed in I know it's rare it's why I can't find answer anywhere please could someone help me with this .