@Perry_L1gon,

Normally the solution is to disable 5ghz on the main network, setup the device, and then re-enable the 5GHz, as can be seen in this thread for the La Crosse Weatherstation

I would recommend first attempting to use the IoT network again, however, try a lesser encryption method.

Since you have found the device in your client devices, try or make sure that the option for mesh technology is also disabled.

Unfortunately, I don't know how the display and system connect and play with each other, but I would imagine that the display will connect to the station directly, so definitely try moving your devices closer. 

If they connect via your network, they may be having difficulty connecting through a node - make sure that there isn't two devices attempting to your network - if there is, you likely need to disable the same settings as you already have.