@lukeheald To you Sky connection the type of data is irrelevant it is just bits of data in packets requested bybthe router as long as the amount required is within the bandwidth available it gets through. So first question how fast is your Sky connection at the router? Easiest way to measure that is to run the connection test in the My Sky app dont rely on Speddtests as those are measuring speed at a device and it is the feed to the router we are interested in here.
Then look at whether that bandwith is sufficent for the number of devices needing data at the sametime. Each Sky Glass TV or Stream Puck needs a constant 25Mb/s to stream UHD video, that can vary but UHD sport typically needing the most. HD video that drops to 10Mb/s. Gaming however needs less 5Mb/s so check if your problem is a lack of bandwidth which in these days of fibre connection is rare but if you are on a long copperl line that could be a factor for you.
Second major factor is speed and reliability of the network connection gaming or streaming video over wifi inevitably increases latency and jitter which is why whenever practicable ethernet is the preferred network connection. You say you have tried a replacement router what did you buy and how are your console and Glass TV and any pucks networked?
Its the router that sorts out which device gets what data packets and whether some trafiic gets prioritised. Basic routers work on a first come first served basis which is great most of the time in most homes but they lack a feature called QOS which typically more expensive routers sold for gaming offer which prioritizes gaming traffic. The downside is if you prioritise one type of traffic something else gets worse treatment and could cause issues with Glass TVs in particular.
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65inch Sky Glass, 3 Sky Streaming Pucks, Sky Ultrafast + and Sky SR213(white Wifi Max hub) main Wifi from 3 TP-Link Deco M4 units in access point mode
