I am also using Waze 18.104.22.168 on Android 4.1.2 on a Droid Razr Maxx HD (Verizon). So far waze has been stable for me. I've had a couple of crashes here and there, but nothing major. I can view my scoreboard without problems. So this doesn't seem directly related to the hardware to me.
As you are having problems with the scoreboard and with the pop-ups (and ads) that should display when you come to a stop, my guess it is some problem with how waze is attempting to retrieve internet content on your phone.
I'd be glad to compare settings, but we've about reached as far as my technical knowledge goes. Maybe others can comment on the best way to remove and reinstall.
Regional Coordinator: Mid-Atlantic, US
Verizon, Nexus 6, Android 6.0, Waze 22.214.171.124