Addon version
11.1.1

World of Warcraft Version
Retail

I did not see any ticket mentioning this, so I hope this is not a duplicate.
Love your addon and would hate to change to anything else ;(

Issue
Pressing any skill that does invoke a CD will not be reflected on the action bar.
It will however update when you hover over it.
People on curse also mentioned that the highlighting of procs does not work properly.

Does this happen with just Dominos + Dominos_Config enabled?

This occurs regardless of whether dominos_config is enabled or not for me in respect to CD being shown, and the behavior is the same for whether OmniCC is enabled or not either.

Your question made think and I didn't disable all my other addons before posting :(
Switched them off in chunks and turns out that I had the weirdest, outdated addon that would reproducibly lead to this issue: Talent Tree Tweaks.
There's a different addon called "Talent Tree Tweaks | TWW" that doesn't break Dominos.
Hope that helps other people having the same issue.

Sorry for wasting your time and thanks for the quick reply!