I see a lot of threads about the undo not working properly, and how the preview doesn't update until you click somewhere else or wait several seconds. Some say the problem was fixed in 13.7. Not me. Even tried making a new project, clearing the cache and making a tiny circle. Moving the circle then undoing just leaves the circle there, like so:
Some info on my hardware and software, in case it's important. It's just a stock Macbook Pro really.
After Effects 188.8.131.52
MacBook Pro (Retina, 15-inch, Mid 2014)
2.2 GHz Intel Core i7
16 GB 1600 MHz DDR3
Intel Iris Pro 1536 MB
What OS are you running? I'm not seeing that issue on my Mac or Windows machines.
(I know you're using a Mac, but you didn't specify your OSX version and you might be running Windows on it with Bootcamp. )