Sudden fish death

[JaredShope1]

I had a potbelly molly named Tigger for about 7 months and it randomly died. It was totally fine in the morning, eating, and swimming normal. Then I came up later that day and it was stuck to the filter and dead. A couple of days prior to this, I saw my one platy get stuck to the filter too, but was able to save it and now it’s fine. It’s so strange this happened again but this time the fish died, even though it seemed totally healthy. Any idea why?

 

[SaraB]

Is potbelly another name for balloon molly? If so because of how they are bred and how short their bodies are they have a notoriously short life.
What are your water parameters? What is your water change schedule?