I remember having a similar issue but that was way before using "Critical outside VATS" and it mostly happened after jumping into a PA. It was also totaly disabling "HOLO time", forcing me to reload the game to re-enabling it. Installing "FallUI - HUD" seems to have resolved the problem.No it's not, because nobody else has mentioned it, and I don't think I'd ever said that until now.
It's just a theory, but I suspect the way that spams 'corner messages' every time you get a Crit is breaking that subsystem.