5 fish died all at once

[parrotonmyshoulder]

This happened last weekend. We came home to find 5 dead fish. 3 guppies, 2 neon tetras.
Rest of the tank seemed fine and still are a week later.
All water parameters are completely fine.
I need to replace as the groups are too small now.
Current fish (125l tank): 3 neon tetras, 6 phantom tetras, 4 guppies, 2 otoclinus catfish, 1 swordtail
Has anyone had this happen? It’s so strange.

We've just had quite a few deaths and think it might be neon tetra disease.

Have you considered this?

Sorry to hear about the fish x