Google Maps, not shown, had exactly the same problem. It repeatedly told me to turn around and tried to direct me onto a freeway (out of my way, but theoretically a possible route, I guess) and then it told me the road was closed, then got lost and decided we were nowhere. We still had coverage, and the downloaded map remained, but we weren’t on it.

Google maps does not know Newcastle, incidentally. It has repeatedly sent me on circular loops around my destination in Newie, and insists the tip has an entrance that doesn’t exist, among many other inconvenient wild goose chases. It’s fun to use, but gets massively unreliable outside Sydney. I cannot trust it, so I have both and check both when starting out.