Recent key isn't working after rebuild

Hi!

My screen cracked and I replaced the digitizer, screen and daughter board (tools and parts all purchased from ifixit). When I put everything back together the recents key lights up (with the back key and yes the back key and home button work) but does not respond when I tap it. I tried updating the phone followed by a restart and it still doesn't work. Does anyone have any suggestions as to what this could be??

Thank you in advance!