I've been noticing lately that while in space combat, several chat windows will scroll themselves with what appears to be blank lines, pushing any text up and out of the window. In the process, it also appears to be deleting the visible text, as you cannot scroll upwards to see it again as you usually would.
When switching characters after this happens, if the afflicted chat window is open, you'll briefly see a flash of color as the text is revealed, right before the character logs out. I took a video of it the last time, just to see if I could capture it, and found that it's possibly some sort of bleed from the combat log.
I'm not entirely certain that it's restricted to just the combat log. Usually the color of the text is orange or red, though a few times I saw blue, which is generally the color for NPC messages. None of the related channels are active in the windows that are affected, yet their text will end up there, invisible until you log out.
I've tried deleting the chat windows, and recreating them from scratch, but it doesn't change the behavior.
I can't recall whether I get this during ground combat or not, I'll have to run some Colony missions and see, but it definitely happens in almost every STF I run. I don't notice it as often in solo runs, so I'm not sure if there's a connection there or not.