Ive got the same issue since a couple of days. Sudden lag spikes in pvp as well as pve. Mostly pvp but thats what i play most, so thats subjective. It stays unplayable (avg ping about 1000ms for some time and dann goes back to normal. Evenings and weekends mostly. Im in EU Region located in Swizerland. Its nice to have a deserter buff bc loadingscreen takes forever after dc bc of the heavy lags. Dc happens not often but it does. Other Games and i-net work fine in the same timeframe.
Other Players on the Map are complaining too in the same timeframe so i think we are definitly not alone…
Today after I was back in the Mists it was fine again, but that was not always the case.