@Candice17 unless the buffering is restricted to a particular app or channel the issue is likely to be dodgy wifi. Not sure what tests you have run butvthe important one is the Network test innthe Get Help menu of the Netflix app as thst measures speed at the puck. You need around 35Mb/s to stream in UHD.
However bandwidth is only half the story if your WiFi is affected by interference from your neighbours' wifi networks or from electrical kit in your home thst can also cause buffering as data packets get lost and have to be resent. You msybe lucky and simply rebooting your hub can help as that makes the hub find the least congested channels to use. It is also worth making sure both the hub and the puck are out in the open people love hiding the puck behind a wall mounted TV which msy look neat but the TV blocks most of the WiFi signal.
Beyond that if you can use an ethernet cable to the puck do so otherwise consider improving wifi in your hime by either buying your own kit or paying for Sky's WiFi Max package. I have used SkyStream/Glass since launch in 2021 and it works very well when given a decent wifi feed.
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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
