It seems obvious that someone miswired that hour meter when they installed it, or when a repair was made.
If you are not good with electronics yourself and need help, I highly recommend Nick of Northeast Marine Industries out of Meredith.
I've seen him work on other boats, he knows what he's doing, does a great job. He'll come to you as I've seen him often working out of his truck at our marina.
https://nwmarineindustries.com/