Apple Carplay split screen not working - ** FIX **

I have seen a few comments asking how to fix an issue where carplay split screen does not work. Unfortunately those threads are closed for replies, so here is how to fix the problem:

Very simple - reinstall Apple Maps

I uninstalled Apple Maps originally because I use Google Maps and did not want to waste storage on my iphone (and because I am a bit OCD about having a pointless app on my phone). It turned out the the split screen function required apple maps to work!