LEAP 15.1 Strange power problem with Acer laptop

My wife's ACER V5-571 laptop exhibits a strange problem. If we run it and then power off it will power down and then immediately power on again, if we power it up and then do nothing but hibernate it will do exactly that and power down OK, if we run it for a while doing stuff like email and web browsing it will not power off at the end of a hibernate process. I have tried both hibernate and shutdown from a console and using the KDE menu items but the problems are the same which ever I use. The laptop is fully up to date with fixes on Leap 15.1. With regards to the hibernate it does have a large swap some 3 times bigger than the actual memory and swap is active. Also if I wait for a couple of minutes after it will not power down from a hibernate I can force a power off using the power button and it will resume OK!

Now I have no idea where to start debugging this so I guess I'm asking for pointers for things to try?

Stuart