Originally Posted by Zandel

Probably has something to do with internet providers then, I'm Australian so other than rather slow internet (compared to the rest of the world) my connection is stable and reliable. I know a lot of American ISPs are not as reliable and tend to restrict odd data flows at times for no obvious good reason.

That's one of the things I've been thinking of. I'm from a country that shall remain unnamed (not American), and the internet connection has been, shall we say, not flawless for as long as I remember. I didn't immediately draw a connection to that as I am so used to that problem (and as the same problem had not happened before this last maintenance). But it could be.
The other thing I can imagine, and the one that is my primary theory, is a difference on browsers. I base this on my experience that sometimes when one game element doesn't work in one browser, I can use it in another until it gets properly dealt with. (For example, once for a day I could only use my garden in Firefox. But that was a while ago, I forget when.) So the first thing I tried is to play the game in different browsers. One browser I am unwilling to use though, for my own reasons, is Chrome; so maybe it was working in Chrome long before other browsers. Is that what you use?