I actually never had experience in the lag that a lot of people have been talking about for awhile until this last week. I was working through my Skyscale Collection (I had been working on it slowly for the past few weeks without any lag whatsoever), and in Thunderhead Peaks while I was farming Branded Mass, I joined a North Meta run. It was only slight lag initially of maybe half a second or so, but once we got to the finale of the run, we started getting insanely high lag spikes that would lag for almost 10-15 seconds consistently. Others in the squad with me confirmed that they were also experiencing the same lag, so that confirmed it wasn't on my end.