In other words, given the car icon isn’t displayed at the bottom of the maps card on the dashboard, you can no longer see what’s ahead, as the available map estate has been reduced substantially.
I noticed the same behavior on Waze for CarPlay in my car too, and by the looks of things, this doesn’t seem to be related in any way to the iPhone you use to power the whole thing. I use an iPhone 11 Pro, but I’m seeing similar reports from iPhone 12 and iPhone XS owners too.
Others claim a similar bug happens even when running Waze full screen, with the car icon again displayed at the middle of the map.
For the time being, however, the Waze team is yet to acknowledge the issue, so it’s hard to tell if a fix is coming or not. However, given the number of reports in this regard is increasing, there’s a good chance Waze developers will look into the whole thing and come up with a fix rather sooner than later.
In the meantime, there’s not much you can do to fix this yourself, but as I said, the whole thing appears to be happening randomly. What worked for me was to disconnect the iPhone from CarPlay, manually close Waze on the smartphone, and then reconnect the device to restore the expected behavior on the dashboard.