heating system not working - thermostat error 0097-00003

It is snowing and my heating system is not working. I keep getting the error  0097-00003 (see the screenshot attached).

 

I have already tried the following:

- Restarting my router

- Restarting my netatmo by removing the batteries

- Restarting my thermostat tile by unplugging it for 60 seconds

- Restarting my phone

- Removing the netatmo accessory completely from my home and adding it again

 

The thermostat keeps being impossible to connect to the wifi....

The wifi is a 2G network created specifically for the netatmo, that had been working well until now, when apparently for no reason it stopped working.

 

I recently migrated to the new control app .... can that be the issue?
I also can't connect to the thermostat on the netatmo app...

 

Please, I appreciate your help asap, it's very cold!