Just for full disclosure, it had been happening for some (though not always like now) in my previous game, but it was "refreshed" when I would click on a different city (so kind of annoying but, frankly your UI is so much better than the default that it was still worth dealing with).
Current mod list:
Chos Quick UI (yours)
DLC: Aztec Civilization Pack (default DLC, so I doubt it's the issue)
GDG's Vuilder Every Wonder Boost for chosen Civ (was not active in prior game which also saw the issue)
Historicity++ (corrects some historical errors in the civlopedia... i can try disabling this one but I don't believe it interacts with the UI at all)
Next City Plot by Ace (you said on the front page that this is compatible with yours)
TCS Customizable Warmongering Penalties 1.1 (in a moment I shall try disabling this one as well for error checking, but it doesn't look like it effects the UI at all either)
Unit Report Screen (also supposed to be compatible with yours)
I shall do some new game experiments with various combinations of the above to see if I can pinpoint one of them being the issue (starting with only using yours in case that in and of itself is somehow problematic).
---Edit---
I forgot to mention this before, but I did notice it happened a lot more frequently when I would change what the city would build, then exit, then go back in. Not sure if that helps error check at all, but if the roles were reversed, I'm sure I would like every piece of info I could get.