Zones have disappeared and you are unable to add them.
Zones have not disappeared and I’m able to add them.
So try to be more specific… 
I used to have 2 zones that showed up on this map around my home. They are no longer there. I tried to add one called test and nothing shows up. They both still show up in the entity list and can track as I come and go. They just do not show on map and there appears no way to add or change one.
The question was clear on the first try. No need to specify that.
As we, volunteer helpers, do not own any crystal balls, we need info on your HA instance.
Home Assistant Yellow. Latest OS and Core.
Problem fixed itself overnight. Close issue.