No problem here. How strange. I take it you mean the reaction doesn't appear for your characters in the Reactions tab?
Nothing in the reaction tab, no little icons just above the hotbar and no attempt at an OA if an enemy moves away during combat. It could be a mod doing it but I have mods which make things more 5e not less 5e.
I think it worked in EA but it is a while since my last EA run. The mods are pretty much the same as they were then (but now all full release ready).
