I had a similar 'bandwidth' issue with my Jio Router. But in my case, my nvidia shield tv pro was buffering when streaming 4K rips from my NAS. Both were connected via Lan cable to Jio Router. And this starting happening all of a sudden without me touching any settings on the router. Tried everything I could including resetting/formatting both my devices. Ultimately called Jio technician, who came in and just reset my Jio router
. Everything started working fine after that.
You may want to do this as a last resort. I suspect Jio pushing updates and/or messing with router settings remotely.