Having the same issues right now. This actually was an issue before when MD started migrating to a new server that lasted for like 3 days or so. After that it went back to normal for a week so I thought it was fixed already but it seems like the problem persists.
Also wondering the same thing, most of the time it's stuck at either 50 or 60+ series and it doesn't go any further. Sometimes it went back to normal but only for a couple of minutes.
The updates pages seem to be stuck at 1 or 2 pages with only 60+ series visible most of the time and you can't proceed any further. Sometimes it fixes itself but that hardly ever happens and it only last for a couple of minutes. I have tested on other browsers besides Chrome and the problem...