I have this problem where my male dovii gets aggresive towards her mate after a water change, sometimes the aggression even starts during the water change. What I normally do is scoop up the female and place her on a plastic cage to protect her from the male. The female is released from the cage the day after. The male no longer atttacks the female after this.
I was able to solve this by doing my water change at night and then closing the light, no lights, the male and female just sinks to the bottom and do nothing
A small amount of light is enough for the male to zero in on the female, so you should observe that both fishes sinks to the bottom when you turn off the tank lights and the room light. I use a small flashlight to check that the male is sitting still and not pestering the female
I was able to solve this by doing my water change at night and then closing the light, no lights, the male and female just sinks to the bottom and do nothing

A small amount of light is enough for the male to zero in on the female, so you should observe that both fishes sinks to the bottom when you turn off the tank lights and the room light. I use a small flashlight to check that the male is sitting still and not pestering the female