Take it to your local tip, to be honest that's where all Sky Glass TV's belong, 3 years of constant hassle. And I don't think it's going to get any better with Glass 2.
Part of the problem is Sky can't help themselves but to push new features to it every couple of months, every 6-8 weeks there is something new. Why on earth Sky can't just do a big update every 6 months is beyond me, and fix bugs in between.
Is just seems Glass in which ever form is in a broken state to varying degrees, and folk are simply to invested to just discard it. And mark my words, give it 2-3 years Sky will stop supporting Glass 1 and if folk don't upgrade the only option will be to connect a puck to it, at which point I will put a sledgehammer to mine and dump it at the tip where it truly belongs.
This lip-sync issue has destroyed any confidence in a product other than set-top boxes made by Sky.
