Change of Internet Provider Problems

Yet another thread but...
I've just changed internet provider. Using both the phone/laptop and different browsers I can't connect to the dongle. The Givenergy app takes me through the steps but fails to connect to the dongle. Attempting to connect via 10.10.100.254 just times out via the browser. Is there a reliable way to fix this without having to access the internal dongle on the inverter? 5.1 Gen 2.

Go into the settings of your new router and set the WiFi SSID and password to what it was on the old router.
You may have to turn the 5GHz WiFi off until you are all connected

DaveCole or if you still have the old router, you can power it up and connect to dongle through that to reconfigure it.

SteveCook what a bloody faff in the 21st century!

DD I actually tried that but it doesn't respond. I can see it as an available network.

DaveCole but it doesn't respond

What's "it" here? Does the old router show the inverter as connected (eg in DHCP tables) ?

DaveCole
I agree, but the other way is to change all the connection details on all the other wifi devices in the house to connect to the new router. I change the new router SSID and password to match the old.
That way when my kids come home to see mum & dad now and again I dont get squeals of "can't connect to the wifi" when they bring their fancy phones!! that they seem to change every few months