I've been streaming Sling TV for a couple of years now through Roku and it's never been right: very slow to connect, picture freezes or goes dark, etc. I don't have any problems with any of the other channels - Netflix, Amazon Prime, Hulu, etc. - that I get through Roku. I've been on the phone this week with both Sling and Roku tech support, they walked me through all the steps, even trashed my Sling app and downloaded a new one, but no improvement. I upgraded my internet service with Comcast 2 weeks ago and get excellent connecting speed so that's not the problem. Not many internet devices in the house limiting the bandwidth; just me and my wife, no kids with games, etc. Arrrrgh! Has anyone else been through this with Sling? Any suggestions appreciated. Thanks.
YouTube TV, Fubo, AT&T Now. Those are just a few.
I rarely have any issues with the Roku, but the Sling on the Firestick has been pretty bad lately.
My guess is that Sling requires either a strong internet connection, or a device with good processing power - which the Roku has both over the Firestick.
Either way, I think the device you're using is likely the culprit. Try doing a factory restore on your Roku to clean it up a bit, or add a memory card to it if yours has the microsd card slot.