Is there an issue with the S6 and WiFi connectivity?

[AC Question]

I have 6 devices on my home WiFi network. I have had no issues with any of them, including the S5. Now that I have the S6, it connects just fine because I can print to my ePrinter from it via WiFi. However, no apps will work with WiFi on, yet they all work if I use my data (which is all used up!). This means no Netflix, Prime or games. T-Mobile says its Xfinity, Xfinity says its T-Mobile. After days of troubleshooting I have decided its the S6. If it looks like a duck and quacks like a duck, guess what - its a duck.