Home button failed after opening up but no repair carried out

So i opened up an iphone 7, used a hair dryer to loosen then a pry tool gently to open bottom left, then lifted it open with my fingers. It had original seal but opened easy enough.

Once opening, i couldn’t carry out any repairs, as the y screwdriver i had been provided was too big.

so i closed the phone back up. upon restart, no touch ID, and no home button. WTH… ??

Any ideas how this can be? The home button wasn’t touched or disconnected in any way, either at the screen end or the main board end. there’s no damage to the cables at all. the protective plates that hide the connectors were not even removed.

There’s no signs of damage to any of the visible ribbon cables, or the back of the home button. nothing was inseted into the phone, once the bottom corner was lifted, the rest was done by hand. The only thing i can think of is that the extention cable (the one attached to the screen itself) has either been damaged (even though theres no signs) or the connector has manged to disconnect from the mainboard whilst still under the metal plate?

can literally just putting the slightest amount of tension on the ribbon whilst lifting the from off do this? or the heat from the hair dryer?

Any info would be much appreciated.

thanks

Adam