Suggestions.
a) Get a faster model. If you have a first generation Fire stick (without the mic remote), this is a very slow stick to being with.
b) Wait for direct tv to release an updated app (complain to amazon to encourage this)
c) If you're Wi-Fi is built into your Internet modem, get a separate Wi-Fi router. It is a well proven fact that all-in-one Router/Modems have poor and unreliable Wi-Fi performance. You should be connecting to the faster 5ghz frequency on the Wi-Fi router.