Normally the wifi disconnection will be recovered in 20mins.
Most of the disconnections had happened because it loses the connection with the router. The energy meter will try to re-connect the router every 20 mins.
if it had not recovered for a long time.
Please let me know
1 whether the led of wifi on the front panel is still on.
If so, please try to visit the local IP, and check whether it is still accessible.
how to visit the local IP please refer to
2 whether the SSID of iMeter_yourSN appears around?
if so, please connect to it and log in to the IP of " 18.104.22.168" , like you configure the energy meter for the first time, and check whether the SSID of the wifi configuration had been set to "test"