I noticed this issue happening quite frequently this weekend on my trip up and down US Hwy 77.
While driving on route, I would notice sections of the map where the road was visible but the purple line showing the route would disappear for short stretches. When I would get into one of these areas, the distance to next turn number would no longer update, although the map would keep scrolling with my current position. As I would get close to the point where the route re-appeared on the map, I would get the spinning Waze icon and the directions would change to "Proceed to highlighted route" with the distance to my next turn listed. Then after driving a short distance into the area where the route reappeared, the directions would change to reflect the correct next turn with the distance.
Showing the multiple "missing" pieces of the route
As I was nearing the end of the missing section and moving into where the route reappeared
This problem only appeared to happen on US Hwy 77. I didn't have any issues on I-35 or any other roads I drove over the weekend. I thought it might be an issue with cell service that was causing missing map tiles, but I did a refresh of the map in a few areas and it didn't change. I also had full coverage in some areas where the problem was occurring.
I typically use auto-zoom based on speed so that I can see a long distance ahead of me on the map when at highway speed. When I was reaching one of these areas last night, I zoomed the map into a closer level and noticed this at the beginning of a few of these areas.
It appears that there is a missing section of the road that wasn't visible when zoomed out. The missing piece is extremely short (less than 0.1 mile). When I look at the map in the editor, nothing appears to be missing and everything is connected properly. This "missing" segment is also in the middle of a long segment in the editor that doesn't have any intermediate junctions. And since Waze routed across this section with no issues, I don't see how there could be any missing connectivity. But it also seems to be too short to be a tile that wasn't downloaded since I can see detail in the surrounding area.
Any ideas what may be causing these issues?
AT&T iPhone 6s iOS 9.3.2