Hmm. I can't figure this one out. The problem with this intersection also seems to manifest if you turn left from Church St onto Main, where you get no turn instruction at all.
Typically, waze will give a "exit" instruction anytime you leave a highway segment with only a slight angle. But here the angle looks close enough to 90 degrees that it should cause a turn instruction. There seems to be something about the intersection that is making waze treat it as a slight angle rather than a sharp angle. I don't know what it is though.
Area Manager: Annapolis, Maryland, US
Verizon, Droid Razr Maxx HD, Android 4.1.2, Waze 184.108.40.206