My largest city Chapter 18, does it but my wife's, Chapter 15, does not. And my beta chapter 8 city, never.
Operating system: Windows 8.1
Browser Firefox, Opera, MS Edge and all three do it in my largest city
Places it occurs (in order of frequency) Trader, Neighborhood, Main screen when moving things around.
Also, my system starts fast but starts to slow down after 10 minutes of work and gets progressively slower...until I restart, then it's okay for...another 10 minutes. But that was occurring before the freezes.
I'm wondering if it's the amount of buildings I have. My moonstone farm is pretty large and all those 1 sq building may be a problem. Anybody know?
So that's my off the top of my head response.
AJ