For Stamina, you should check you 3G speeds. I've been using android since it was originally released. I"m also on Sprint, which is not known to have high speeds. It's been working fine. The other thing you may need to do is open up some ports in your firewall. Check your setting in your PMS and you should see something for port. You may want to manually set it, so when you open the port it doesn't change if you have to restart the PMS.
As for Goros, you don't need to use dyndns/pay2play. It's a useful tool if your ISP changes the IP they give frequently. I would suggest looking up your IP (whatismyip.com
), and just manually input it. Plex does a good job after that. I know with ISP, my IP has changed only two or three times in the over five years I've used them. Plus, it'll take away a variable Also, are you able to connect to the PMS when your on your local network, from whatever device?