Hard to describe in a one liner, but here's the problem:

Get an upgrade that gives more movement points for your army? You'll still show 3/3 instead of 3/4 or 4/4 until next turn.

Cancel the build of an 'enveloped' resource that's in your city's build queue, then rebuild it? It won't show up in the build queue until next turn.

Capped on food and a farm just finished this turn? City details/growth tooltips will still show growth capped due to food, despite having just increased your food supply.

There's a few other examples but I can't think of them off the top of my head. Basically it looks like the UI simply isn't updating until you hit End Turn.