I've had virgin 350 for roughly 2 months now and up to now its worked without issue I can get for example a 25gb game downloaded in roughly 24 minutes or so. As of tonight I notice my speeds have dropped massively and aren't a fair representation of what I'm paying monthly for. Generally my speeds would go up 40mb per second which would really get through a download in good speed but now my downloads start off around that figure only to gradually get worse to the point that downloads then to to 6mb per second. So a game such as bloodborne has gone from being downloaded in 24 minutes to two or three hours. My ps4 is set up via LAN and I've tried turning the router off and on again and that hasn't solved the issue.
I've done some reading up online and Sony announced at the end of the month and Sony have announced they were planning to lower the download speeds due to the lock down to ensure the network doesn't crumble due to the higher demand on their services due to the lockdowns world wide.
I'm hoping this is the issue as I've seen several stating this is what could be happening.