Upper, under or both top and bottom leaf surfaces? That rust colored powdery, feathery, or even furry coating can be normal for some.

Photo would help...

Or see Indumentum Rhododendrons - images, your favorite search engine

Not much to show on a pic... When I take my fingers and gently rub the surface of these new leaves (does not affect the mature leaves) fine sticky rust colored powdery stuff becomes evident. I don't know, maybe it is normal. I just never noticed anything like this before. I'll let it go for a while & see if it disappears as the leaves mature. Thanks anyway.

It is a feature, not a problem. It is tomentum on the top and indumentum on the bottom. The tomentum will eventually disappear, but the indumentum usually stays. They prevent insect damage and help prevent desiccation.

Here is a link that might be useful: Indumentum and tomentum

Thanks rhodyman, never really noticed it in all the years I've had them.