Sick Nannacara, what could it be?

[Epiphyte]

I've had this female Nannacara for around 9 months now, I've got one very healthy male and this female who vanished for a good part of 4-5 months. I thought she had snuffed it but I spotted her one day sitting on the bottom of the tank before she swam off for another few weeks. I spotted her again with what was a case of fairly mild pop-eye. I've dosed 4 days (tomorrow is 5th and final) of myxazin and the pop-eye seems to have cleared up, but she still just sits on the substrate of the tank.

Breathing is normal, no white spot, looks healthy aside of lethargy and inability to swim off the bottom of the tank.

Any idea what this could be? I'd be gutted to loose her as Nannacara are my favourite fish.

 

[Luciën]

Don't really know but I do know that males and females with nanacara are hard to match.. They love to attack if they don't like each other. Though they leave all other fish alone. Maybe she got a hit from the male or suffers from stress?
Anyway good luck hope that she comes around, they are one of my favorite cichlids too.