Hi,
Try replacing the Power button
Here’s a link to the ifixit [guide|106308] guide, which should help.
Replacement power button flex cable parts are not that expensive.
Here’s a link to just one [https://www.mobilesentrix.com/power-button-flex-cable-for-lg-tribute-hd-ls676|supplier]. It is only shown to give an idea of the cost of the part and what it looks like. There are other suppliers online that may suit you better. Just search for ''LG Tribute HD power button part'' to get results.