@Albatross you need to go back to Sky as the remaking of the fibrecweld and swapping hub has not helped. Some of these faults can be hard to pin down so the standard method is to replace things until the fault goes away. On average full fibre is far more reliable than the copper network so your fault is unusual.
If there is an issue with the fibre feed you would expect to see a red light LOS on the ONT when it loses connection. If the lights stay green check tge lights on the hub (https://www.sky.com/help/articles/hub-lights-explained-start) as they can tell you what is happening.
However you need to talk to Sky to get this escalated so I am escalating your post to the Sky team who support the forum who should be in touch soon to offer you a private online chat session to get this sorted. Keep an eye on the forum as if you miss the message just click the brightly coloured chat icon which will be added to the forum pages for you to use.saving a long phone call.
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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
