There is a common misperception that the "bars" or signal strength indicated on your device are always telling you the truth. Often, they don't represent how strong your connectivity actually is.
We recommend using speedtest.net to get test your download speed when they are experiencing connectivity issues or other video play issues. There's also a speedtest app you can install on your device. Try measuring your download speed and if you're still experiencing problems, send us a note: firstname.lastname@example.org