It's been a long & frustrating situation I can totally appreciate that. When we first spoke about this I wasn't aware of any wider issue but as general diagnostics didn't help I queried a wider issue and was told there wasn't any.
That remained the case for a few weeks until more impacted customers got in touch here. I fed back each example with as much information as possible (along with the comments/suggestions of VIP's here too).
At this stage I'm aware of at least 5 affected users and last week the network team began to take notice.
I won't pretend to understand the technicalities but I do understand that much of this is out of our direct control - that's of no consolation to you as a VM customer but due to the nature of the issue all I can do is chase this from here and I'll continue to do that until we reach an outcome.
Tom