When I have two discus pair and start to clean a site I separate them. They still cleaning the site for about two months and no eggs, and suddenly they start fighting each other. This is the second time that happen to me with different pairs and I think that the third pair that I have, walking on the same road (fighting each other).
Do not separate them from the community tank.
Let them breed there.
They will fight others but not between the couple.
Then take the rest out.
They will bo all the rest of work.