Ultegra 6800 rear Hub and lacing

This is one for all the wheel builders out there, looking for your opinions\experiences re shimano Ultegra 6800 rear hub (32H). I bought the wheels from Planet x 18 months or so ago and they are hubs as mentioned, laced 3x onto Ambrosio rims. back wheel needing truing constantly; almost every time i went out the back wheel would be all over the place when i got back, however, I never once had any issues with the cone adjustment. So, I had the wheel rebuilt with new spokes and as it turned out it also needed a new rim, no issues with that I suppose so new rim, wheel rebuilt by LBS, off I went, only this time the cones on the rear come loose after about 10 miles, had new cones fitted but no change 10 miles or so cones come loose another 10, 20 miles and play is pretty severe. Now, LBS that built the wheel has gone bust so not much happening on going back to them so took wheel to shop in midlands that is Shimano Service centre, guy there before he even looks at wheel asks; 'is the wheel laced properly?' I give him the wheel and he has a look at hub, says hub looks ok but wheel has been laced differently from original build (when cones where fine) he says it needs rebuilding and lacing properly (he shows spoke wear marks on hub to show difference). I take it to another LBS, guy there has been building wheels for 35 odd years and I have a set of DA Hubs on archetypes that he built which are spot on, he looks at wheel and says he would build and lace exactly the same as it is now and so doesn't understand what the Shimano service centre bloke is on about. So after all that, and before I take it back to Planet x for them to see how\why they laced it differently, I am just after anyone's thoughts as to whether they have had any issues similar to this on these hubs, which might go some way to identify which of the people who I have spoken to already in the different shops, is telling me a crock of horse-s**t and the hub may just have to go back to shimano, or fleabay, cheers in advance