weak connection and not able to view or find my device

I don't know if I completely understand.  You said you have hidden networks.  Of course, a hidden network won't be displayed in the network list on your TV.  You need to enter the network name manually, or temporarily make the network not hidden.

Or if that is not the problem, you might need to setup a second Wi-Fi network for your TV.  Here are my generic instructions:

Some devices cannot connect to the gateway's default network.  You want to leave this network alone and AGREGAR a second network with the + sign at the bottom of the Network tab in the T-Mobile Internet app.  For this new network, set the band to 2.4 GHz y set the WPA version to WPA/WPA2.  Try connecting your TV to this second network.  Use the default network for your other devices, as much as possible.

Here are the T-Mobile support instructions for how to add the second network with the app.

Android  How to create additional Wi-Fi networks | App T-Mobile Internet | Android | Asistencia de T-Mobile

iOS  How to create additional Wi-Fi networks | App T-Mobile Internet | iOS | Asistencia de T-Mobile

How to change encryption mode:

Android  How to change the encryption mode | App T-Mobile Internet | iOS | Asistencia de T-Mobile

iOS How to change the encryption mode | App T-Mobile Internet | iOS | Asistencia de T-Mobile