| Yep..........they all do that sir
It's down to the throttle tube ducati use.
It's noot going to harm anything, just looks a bit unsightly.
As for fitting them, you can of course get Renthal Grip glue but you can use several things to fit them.
What you want is something that will lube the grip enough to slide on but then set to hold it in place.
I use carpet adhesive (aerosol), or just plain old bostick. Hair laquer is another one! | 
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