Had tremendous amount of lag yesterday in AK as well
At one point I could not even target my tank... Had to "Return" to entrance to fix it
I also had moment where I saw the whole team freezing then things going back to speed and everybody had taken damage that I did not see
and the red fire circle hit me everytime, even sometimes there were no red circle at all...

but I think this will be the case everytime the tome resets. Everybody goes to AK to cap the mytho so the first 2-3 days of cap reset might always be very busy...