For me - this is the exact experience with Virgin. The FTTP network here they bought, and they clearly put customers on before they'd finished remediating it onto their network. We had multiple outages that were 6+ hours long in the day, looked like they were adding diverse links / replacing backhaul for some of those.
To me, Virgin treat you like they're doing you a favour by you being on their network - forgetting that you're paying for a service. Raising complaints with them is pointless, I had a 3+ day outage and the response I received (eventually) was "well it's working now" and they closed the complaint...
If they did the same to you, that they did to me - about 6-8 months into service it'll calm down. Check if there's any other Virgin works going on in the area, for me it was Virgin W/OR engineers (supervising?) putting stuff in OR Ducts were my worst outages.
Though if they don't sort it - currently going through CISAS (CEDR) with them for my partner because they're incompetent. (cedr.modria.com) -
https://www.cedr.com/consumer/cisas/reports/
Keep it handy just incase you end up needing it