Firmware 1.1 and beyond’s new network screen shows what wifi signals the controller is seeing. Select one, then input the password to connect. If it does not see your wifi it means your controller and router/extender are too far away (must be within 10ft and clear line of site).
While other devices may connect, the onefinity controller has no antenna and may still be too far away to connect. The computer inside is a raspbery pi 3b. It has NO antenna. Then, it’s now inside a metal box, therefore becoming a faraday cage, further decreasing its ability to connect. Just because your other items connect (like your phone, which has 10s of feet of antenna wrapped up internally in the phone plus a plastic or hidden slot through the metal for signal to escape, does not mean the controller will.
A simple resolution is to place an extender within 10ft and clear line of site of the controller. Better yet, a ethernet line is always, the best and most absolute way to connect computers to networks, especially if the optional networking capabilities are an absolutle necessity to your workflow.
If the controller connects one day and does not connect the next, it’s typically one of two things. First, the extender/router is too far away and the signal is going in and out (must be within 10ft and clear line of site). Move them closer together. Second, your router/extender is setting up a dynamic IP address (that changes every so often according to the routers needs, could be hours, days, weeks) and the IP address is changing. Look into setting up a static IP address (this is done with your router/extender, not the controller). More info HERE.