Hi @Stu011 and welcome to the forum. It's difficult to know from the amount of information you have provided but assuming it was working and your Stream puck has simply lost the WiFi connection the following always helps me get it connected again:
Put your Glass or puck into Standby and then unplug both your Glass TV (or puck) and router. Leave for a couple of minutes and then plug your router back in and wait for it to finish rebooting. Once it has rebooted plug your glass TV back in and when that has also rebooted it should have reconnected to the internet
If that doesn't resolve the issue then have a look at the following links to see if they help:
https://www.sky.com/help/articles/sky-glass-no-internet-connection-osm
https://www.sky.com/help/articles/connect-devices-to-broadband-start
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