Tethering to R2

I have been Tethering a Visible R2 Android model Z5151V with a GL-300N-V2 since Dec. It stopped working and I assumed it was the router. I replaced it with a GL-AR150-ext but I can’t get it to tether either. Is there a fix or do I need to return it?

Did you upgrade your andriod before it stopped working?

Does it still get IP address?