Dimmer 2 not connecting to wifi

[Bushbasha]

I've got 3 new dimmer 2 that I'm having issues with not connecting to wifi after changing them from the AP. 2 of them I can either go through the app or through the AP but once I attempt to change the wifi they do nothing. No red light on the back or anything. Ive reset and attempted multiple times, nothing works for me. I can set a static and go in through the static ip but still no luck with it connecting to wifi, the app says pending connection.

Any ideas, maybe try and force an update maybe? Which I've tried but didn't seem to work, maybe I didn't do it correctly. 

I have another dimmer 2 that connects ok but gets really hot, I've measured at 60 degrees C in one spot, seems pretty hot in my opinion. 

[Heinz]

What i normally do is when including Gen 1 devices or most IoT devices in general

have the Router open and have it open on the device page. include the device into the network (making sure the SSID and password is all case sensative )
when the device is added into the network you should then see it appear on the network via the Router web UI.
to confirm everything is working with the device when you see it added to the network.

I do a ping test via CMD. and then i login to the device via the web browser.

have a try with that and see if you have better luck