Per Randy's suggestion, I cleaned the optics both top and bottom. The unit was already set for low security/high acceptance. I also have a recycler for the 5's. I read somewhere online, that unloading and reloading the $5's often helps.
Guess what I found? Turns out that about 1/2 of the (quantity of ten) bills inside the recycler were doubled over (folded). I removed them, and then blew everything out with air.
When reloading, like 1CW1 said, some bills were accepted first time....other took much longer.
It doesn't make sense that folded bills in the recycler would have anything to do with the acceptance rate.
However, it appears that things are better now. Not perfect, but better than before.