Undo (Ctrl/Cmd+Z) doesn't work for Markdown

[elijah (Eli the Bearded)]

I never knew ctrl-B would trigger bold. I didn’t know there were any keystrokes of that sort.

Anyway, I tried it, Firefox on Linux, and could not reproduce it.

I mean ctrl-B did embolden and ctrl-Z did undo for me. Could it be a Mac specific issue?