This has been a recent issue, and happens on two different computers on two different networks, using different versions of Windows, but happens in both up to date versions of Firefox and Chrome.
The issue predominantly happens with the fragmentizer (while hovering over the items waiting for their descriptions to come up) and now I am noticing, with the New Year's Shop as I am trying to add the items I want to my wishlist, but the pages keep freezing every few items added. The pages just become completely unresponsive and the only way to get them to go away is through the task manager. It's really annoying and I was wondering if someone else was having this issue. I could understand it with my old laptop, but my work computer, no.
It's been happening a lot with WL lag and stuff, there are multiple threads on the problems & bugs forum reporting similar issues with loading and page freezing when adding/removing a lot of items at once.