Nice informative reply! I did everything you mentioned and more yesterday. Even traced a hard-line into my wall and down the outside of my house to ensure my mesh system wasn't losing packets.
I've submitted a ticket to EA breaking down everything I found. Along with screenshots.
It's a bad routing issue on EA's side. Consistent 9ms ping to googles 8.8.8.8. when pinging EA 10-20ms consistent until the handover from zayo to EA. Sometimes I would make initial contact with Either London LHR or Frankfurt initially, but then would be instantly rerouted across the Atlantic the US VA. Most of the time EA would just route me straight to US VA without the initial EU contact.
I've exhausted everything I can do on my end. It's not over to EA to sort this calamity out