Can’t connect strip lights to app

I’ve had the app for a while and I was able to connect my strip lights to the app through but I had to disconnect them after I got a new wifi router. For some reason it won’t connect even though my wifi router is 2.4 ghz and the signal is good. Any idea how I can fix this?

Is your router dual band? If so even though it has 2.4ghz you will have to separate the signals so you see both independently, otherwise it will keep seeing the 5ghz and not connect.