screen flickering, ghost touches, even after replacement

hello

i dropped my phone, not from to high, but actually white bar flickering and ghost touches happend.

brought it to the apple store, the analiysed the phone and could not reproduce it, and said even if an error would be found, i am out of warranty because of too many scratches in the metal body (from keys in pocket and so on).

ok got it back, and still flickers and ghost touches like !&&*.

so i orderd a replacement screen, swapped screens, and see there, still flickers.

after digging through ifixit, i found a the problem, the flex cables seem to be not fit perfect, so i bent the shield metal above the cables a bit, and this fixed it, ALMOST!

sometimes randomly it flickes for a short time, alot better than in the beginning!

i would like to put some "buffer" inbetween the plugins and the shield, what material would fit - i am a bit scared about the heat and so on? (so the pressure on the plugins is constant)

regards

helmut