On my recent trips by car, I found that if I’m using my phone to run Google Maps for navigation, Arc reliably gets terminated and doesn’t record the trip. But if I use someone else’s phone for navigation, Arc can keep running and not get terminated.
I did notice that Google Maps starts to display 3D buildings so it might be using more RAM now. Don’t know if it’s related.
It could well be! The most likely cause of Arc being terminated in the background in that situation is memory consumption. iOS will terminate background apps if it needs more memory for the foreground app. The most common culprit of this is the Camera app, which wants almost all available memory for taking photos and videos. But navigation apps (and CarPlay) have long been high on the list of other common culprits.
If you’re not already doing so, I recommend also running Arc Mini, so that that’s there as a fallback, to take over recording if Arc gets terminated.
Other than that there’s really not much you can do, unfortunately.
Arc itself does the best it can to avoid that situation, by going fully “headless” when in the background. That means that it discards its entire UI after some seconds in the background, which means the only part of the app taking up memory is the underlying recording engine. iOS will terminate first the apps using the most memory, so when Arc is “headless” it should be low down the list. But yeah, unfortunately it still can happen.