CarPlay using offline maps with 5 bars

[Morac]

I was driving today using Maps for navigation in CarPlay and saw a “using offline maps” text on the map. I checked and I had 5 bars of cellular. I ended navigation and the text went away. This never happened before. I don’t have the setting to always use offline maps set.

Why is Maps using offline maps for navigation?

 

[bransoj]

Was there a phone signal at the point of starting the navigation?

 

[Morac]

Yep. I was on WiFi when I started.

 

[Capeto]

I see that same behavior on my iPhone without CarPlay (using offline maps even though I have full signal), I just assumed it did so to save data/battery life.