Hi Dan,
When I open the map, I cannot see the basemap - please see screenshot.
I'm using wifi - I've tried multiple networks.
I think the Vo LTE thing is something to do with phone using 4G/3G - I've done a random google.
I also just tried going to flight mode and connecting to wifi, to disable phone reception/data - still same problem.
Last thought is I forgot to mention that we're still on Portal 10.3.1 - haven't managed to upgrade yet.
Thanks, Erin