i have same problem since 02.03.16 till now.iphone 7 plus first it slow and front camera not work.then update 10.3.3 not work home key also.then i try new lcd new front camera by other i phone 7 plus.problem same.then i remove front camera flex it work fine.then i used without front camera and home kiy till now.but finger work good properly.last day i upgrade ios 11.now face new problem its slow again......i remove home flex also,problem same.now i remove front camera flex,home flex,sensor flex.its slow same.now i remove iphone from my life.now feel better....