Neither my Iphone 7 or a LG flip phone from work will connect to my Samsung extender. It has worked well for several years. I normally show almost a full signal in my house, but the *48 test fails and so do any calls I try to initiate or receive on either phone. All blue lights are on solid, I've rebooted the router, cable modem, the extender and my phone. Tried all of the suggested troubleshooting tests. No other internet connection issues on my other network devices. I don't see how the advanced calling feature mentioned in some other related threads could affect the flip phone, so I'm assuming the extender could be bad. I did turn it off to no avail. Any suggestions for the next step down the rabbit hole?