Yesterday my three phase meter disconnected from the wifi, and has not reconnected since.  It was installed in October and so far has recorded this grid consumption

The green light is till flashing so it appears to be operational.

I have turned the breaker off, and back on but it still will not connect.

I can access the wifi with my phone when standing next to the meter (I'm writing this post using the wifi)

Do I need to reset it somehow ?

if the Wi-Fi LED on the front panel is off, it indicates that the energy meter is not currently connected to the access point (AP).

The green light is still flashing, indicating that the device is operational.

Yes, if the green light is flashing, it means the Wi-Fi module is functioning correctly. The green LED flashes when the Wi-Fi module requests data from the metering module.

Therefore, the likely cause of this issue is a disconnection between the device and the AP, which could be due to several factors:

1 The Wi-Fi credentials have been changed and not updated on the energy meter.
2 The Wi-Fi signal strength is insufficient; if the antenna was moved, the energy meter may not be able to connect to the AP due to poor signal strength.

Please check whether there is an AP named iMeter_YourSN around and try to do the wifi configuration again.

Like this 

https://www.iammeter.com/quickstart/wem3080t-quickstart#32-set-up-in-the-browser

Please check, when you click the "Wi-Fi networks", if your AP is in the list?