Attempting to duo a world boss today, and my mutagen simply refused to land on the other player. At all. Grouped with them after the first death, thinking this might help (I'm a newish player, and previously put the 'quirkiness' of mutagen down to not being able to heal a different faction player out of group) and still no luck; mutagen just wouldn't hit this other player. They were not using any of the regeneration morphs, so it couldn't be a stacking issue. 30+ casts and none of them hit anything but me.

I noticed back in June in another 'mutagen is broken' thread that @ZOS_JessicaFolsom said that she was looking into this, but never posted in the thread again. Is regen/mutagen ever likely to be fixed? It's kind of a big bug to have persisted for so long.