Angel pair breeding problem

[Stoney Lake Aquatics]

I have a pair of koi angelfish that have produced numerous spawns for me.  Over the past few months the male hasn’t been getting the eggs fertilized and I noticed yesterday the pair is starting to show aggression towards one another.  Has anyone experienced behavior like this and if so any suggestions on what I might be able to do to help them out. 

[Daniel]

Sometimes, two females will pair up and lay eggs. Is it possible that this is what is happening?

On the other hand, if you do have a male and female pair, I have seen pairs breakup when one of the members was unsuitable.

[Stoney Lake Aquatics]

They have produced multiple successful spawns so I know they are a male female pair.  I’ve seen numerous things on pairs breaking up and I’m afraid that may be what’s happened.  The female is on point laying every 11 days and the male follows her in an attempt to fertilize them.  The female will guard and fan them continuously for 24-36 hours and then they start to fungus over.  

[MAC]

I had an angel pair make successful spawns only to turn on each other suddenly one day and have to be permanently separated. Same with an established kribensis pair and also a jewel pair that never had a successful spawn past laying the eggs. In each of these cases the two fish would not live together without constantly fighting. 

I think cichlids kind of do whatever they want.