Home button not working correctly

Hello,

My mom has an iphone 7 plus and the home botton isn't working when in lock screen, when i press the home button when in lock screen the feedback it gives is totally different and it doesn't work, if i long press it does the classic fake click but it continues incessantly and it does not work and even the touch id doesn't work too.

At least if i unlock the phone the home button works perfectly, i tried to use the assistive touch but when i have to unlock the phone i don't know for which reason but it doesn't work.

Does someone know how to fix this problem?