This thread gave me some insight as to what is actually happening.
It is possible to isolate the problematic machines if the players post here what their connecting IP is an if they have any lag at all.

cmd into Netstat will give you the ip but you can also find it via Task Manager -> Performance tab -> Resource monitor at the bottom -> collapse the network tab and check the Address and PID of ffxiv.exe

Mine is always 199.91.189.29:5960
However I have already checked this twice on the open beta and prior to 1st of sept. and the bottom number was above 29, at that time I had no lag spikes.

Just pinged OPs problematic IP an got packet losses, pinged the other ip that was said to have no lag and I indeed got no packet losses.