Experienced exactly the same thing recently after signing up to Voom 3 with 5 statics. Inconsistent speeds, packet fragmentation (even when pushing the MTU right down to under 1300), latency all over the place etc.
Phoned support, like everybody else here, who immediately acknowledged it and stated testing was still underway on "the fix" which is awaiting sign off to move all customers over.
I'm now on Dynamic with a view to move back to 5 Statics when they implement the fix .. but that could be "anytime between now and Xmas" from the support tech assigned to my ticket
