I’ve been a customer for several years and never had a single issue whilst Virgin Mobile were piggybacking on EE.
It seems I’ve been moved to Vodafone as my internet access pretty much turned awful overnight. Black spots in parts of my area (in Westcliff, Essex) that I often visit, hours without coverage whilst working from the office in central London (resulting in missed messages plus a massive hit to my phone’s battery life) and internet slowed to a crawl during my commute. None of these locations previously had an issue.
I know for a fact it is not my handset (an iPhone 13 Pro) as when I tried using it with my work SIM (which is EE) I’m back to the same service I previously enjoyed.
No idea what’s going on but it wouldn’t surprise me if Vodafone are quietly throttling Virgin Mobile customers. I initially put it down to teething problems, but it’s been the case for weeks now. I will probably give it one more week before switching networks (which is now easier than ever before).