The Heathered Storm Leather and Heather Barrel Special Edition headcover comes in a hybrid and that would be my recommendation. A normal fairway might be a bit large for a hybrid. I have not not seen the barrel covers in person, but most fairway head covers that I have by Titleist are too large for my hybrids.

In my experience they fit pretty snugly (especially new) on the 3 wood but i suspect hey would be pretty loose on the hybrid. Better than nothing however IMO.

Barrel headcovers by design are looser than standard headcovers so if you have trouble with standard ones, you might experience even worse slippage over a barrel version. Maybe you can find a new replacement for your existing one through a retailer like 2ndswing.com or go with an after-market design that uses a narrow neck like a knit one or leather with elastic pleats. Best of luck and hope it works out for you.