I find its more down to the app crashing than the car losing connection. When you get the red x like that, fully close the app and re-open it. It often resolves the problem.
So to clarify.
Regarding ZOE 50, we can talk about four issues:
1. The My Renault app works or doesn't work,
2. The connection between the car and the My Renault app works or doesn't work
3. Data exchange is ON or OFF and and
4. The network status can be Unavailable, Disconnected or Connected.
# 1
If you have installed the app properly and created your account, then the app definitely works.
# 2
If Data sharing (#3) is ON, the car is connected to the network (#4), the VIN is entered into the app, the sent code is entered into the app, the app and the car will connect (within 72 hours at the latest, although this usually happens immediately).
However, it happens sometimes the app is useless due to the failure of the Renault server and app screen is something like this:
# 3
You can turn Data sharing on or off. It must be turned on for the car-app connection to work.
# 4
We have no influence on Network status. It can be Connected, Disconnected or Unavailable.
And I have problems with Network status. Without changing # 1 or/and # 2 or/and # 3 or/and car position ... Network status changes into one of three status on its own.