Name: Daisy I Reno, Nv (Zone 6b) Not all who wander are lost
Ok, new thought(s):
You are rubbing off the spots. Don't do that.
Edema - Hoya are waxy so maybe you are seeing 'puddles' under the leaf surface. It occurs when there is more moisture in the plant then it can use or transpire.
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and proclaiming...."WOW What a Ride!!" -Mark Frost
President: Orchid Society of Northern Nevada
Webmaster: osnnv.org