just a follow up as you did remind me to check my other Sling settings...as I noticed a change last night when I reset one of our Amazon Firesticks...we have 4.
If you reset your stick...which we were doing more often when Cox was having connectivity issues, the Firestick seems to override the settings for the Sling app...perhaps other apps. Sling still showed a lower bandwidth, but it was using higher. It was noticeable to the eye. I just clicked higher then lower on bandwidth settings in Sling and the picture quality was degraded.
My assumption is I will see lower usage tomorrow with the settings reset to where they should be. Interesting that the Firestick resets/overrides the app settings.
Just one man's observation.