Massive zone specific lag spikes

Game will be playing fine then upon entering a new zone then ping will go from 30mx to 5000+ for no reason, if i manage to not get d/c'ed the next zone will likely be fine or even if i exit and force a new instance it will likely be ok.

Really annoying trying to do the lab and losing progress.

Have tried re-installing game, increasing shader cache size so far and switching between directx11/12/vulkan, no change.

cheers