s5 active home and recent apps button doesn't work

[AC Question]

after taking it to a shop (have this phone from on a network other than at&t, jailbroken) because it stopped charging. they had it for three days and claimed they couldn't do anything cause it kept frying ports they replaced. i took it to the shop at my provider back home (away at school until this point) and they just cleaned it out and charged it beyond 50% in under two hours. now the home and recent apps button won't work. maybe the incompetent con shop didn't connect the parts properly during reassembly? any idea? maybe how i can fix it or best course of action?

i just got an app for it but i'd love my buttons back