Ener-J wifi relay switch problem

[cully]

I have one of the above WiFi switches controlling my outside lighting from their app on my iphone, working ok
I am trying to get a second Wifi switch to control the DHW heating from the same app (same iphone) but it won't let me
I have gone through the discovering procedure from the manufacturer (Ener-J) as I I did for my lighting but the iphone "cannot discover
the switch when the switch is in pairing mode (flashing)
Ener-J say that there is a probable firewall stopping the pairing but if it worked on one switch why not the other as I aren't aware of any changes made other than phone updates beyond my control??
Any help appreciated

 

[ericmark]

I use android phone, and the Smart life app, and there is a array of options, some devices use zigbee, and some direct with wifi, I have had problems in the past, then for seemingly no reason it works.

 

[Harry Bloomfield]

I have to pair with the Smart Switches app first, then tell Alexa the name of the app I have it paired too. Might that be your problem - though you didn't mention Alexa?

 

[old duffer]

how many different devices can your phone connect to simultaneously. Mine only allows 1