Essence Drain + Contagion Doesn't Work with Allies

When an enemy dies with a contagion debuff from one player and ED debuff from another player, the contagion will spread but not the ED. There isn't any wording on either gem that would suggest both debuffs have to belong to you.

Either a fix or clarification on the wording would be greatly appreciated.

There is only one other post about this and it's years old with no response.