Home button not always working to wake

Hello.

I have replaced the digitiser on iPad air 1, and all worked with no problems for maybe 6-8 weeks.

I now have a problem where the home button sometimes does not work to wake the device and I need to wake with the power button. Once unlocked the home button works as it should.

There doesn't seem to be any pattern to when it stops working, but is normally after a long time with no use, like overnight. But sometimes works fine in morning.

I have tried calibrating home button by holding power until slider appears, then holding home button until it returns to home screen. I have also hard reset, but am still having same issue

Any ideas?

Thanks