one Way bearing?

I have a 2011 grizzly 700 eps 1300km / 180hours.

When i drive in High gear downhill ,and then let go of the throttle, the motor brakes, but after a couple seconds it start rolling freely faster and faster.. Is this normal or is it the One Way bearing? Other stuff?

Sometimes it brakes all the way Down, sometimes it dont..

checked all oil levels, all ok.

Runar
Norway