Bob.. i'm not sure if this is an issue w/4.5 or not.. but i've never seen it before.  on my current render.. my model's arms are bent at the elbow almost to their limits.. and it's almost like you can see the vertices of the mesh through her skin.  Haven't pulled reality back up for this scene yet so might have turned off smoothing or something like that on accident... other than that.. this render looks better at 800 passes that the same model, clothes and lighting did before at nearly 2000 passes