Don't get WD-40 anywhere even close to a bow. It may act as a lubricator, but also attracts and holds grit and dirt which ends up being abrasive over time. No oils!!!!!!
Try any type of silicon spray. Something you might check in the future is how tight the cam is. Could be that the spacing between the limb forks is just a hair on the snug side. The cam should rotate freely. If it's tight you can pull an axle part way out of the limb; enough to remove one of the spacers. Then take a small piece of fine grit sand paper, lay the spacer on it and rub it around to make the spacer a bit thinner. They're only plastic so don't get carried away.
If You're Not Living on the Edge You're Taking Up Too Much Space
Martin/Rytera Staff Shooter
PSAA Life member, UBP Life member
PADI AOW Diver