Harlequin rasbora dying and coming back to life??

[Charchar]

Hey guys

I've just bought 6 harlequin rasbora and one of them has "died" twice and every time I go to fish him out he swims off! He's swimming about absolutely fine now can anyone tell me what's going on??

 

[Aiken Drum]

I found this, looks similar.

https://www.aquariumadvice.com/forums/f12/fainting-fish-9059.html

Sorry, link doesnt appear to work on app, but does on website.

 

[Aiken Drum]

Screenshot in case you cant find it.