hope hubs have never been great either in quality or reliability.
i have soe hope hoops dt swiss rims on pro11.i had the same problem.
what you need to do is seat the bearing in fully against the spacer between the 2 bearings,this needs to be done with care as not to damage the seal on the bearings.
find something that sits on the outside of the bearing & give it a few gentle taps on both bearings.
i modified an old cassette removal tool & the problem has never come back.
to check what i advise is correct is to remove the wheel & skewer & feel the float in the spacer between the bearings ie put your finger in wher the skewer goes & feel the free movement.
i have rebuilt my mates 5 with pro11 hubs 3 times in 18mts for me thats too much.
i have used dt & mavic own hubs no problems for years.