Default T-Mobile Wi-Fi Calling Issues

I'm having a couple of issues with Wi-Fi Calling and wanted to see if anyone else is experiencing the same. I have an LG G2 and whenever my phone goes into deep sleep, I don't receive any calls through Wi-Fi Calling. If a push notification comes through, Wi-Fi Calling will work again until the phone goes back into deep sleep. I have Wi-Fi always on in Wi-Fi settings, but that doesn't seem to work. The only thing that works is an app called Regpon WiFi Keep Alive, which prevents the phone from going into deep sleep. It works great, but it drains the battery. Appears to be a software issue since Wi-Fi Calling works fine when Regpon is on.

The other issue is when someone calls in, they sometimes will hear an echo on their end, but the call sounds fine for me. I'll call back and it's fine. I've brought these issues up to T-Mobile Customer Support, but they just regurgitate the same turn off router and wifi, turn on router and wifi, factory reset, etc. If anyone has a remedy to these issues, particular the deep sleep issue, it would be greatly appreciated. Thanks.