@Neeks1989
LOS is Loss Of Signal, meaning the ONT isn't seeing any light coming down the optical cable. If gently removing and reseating the green optical jack plug and unpowering/repowering the ONT doesn't change anything then you'll need to log a fault with Sky tomorrow morning.
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Sky Glass 55" (on ethernet) & two Stream Pucks (one ethernet / one WiFi)
BT Halo 3+ Ultrafast FTTP (500Mbs), BT Smart Hub 2
