Platformio.ini not visible in tree

I cannot see platformio.ini the tree view anymore.
I still see the .gitignore and the .travil.yml but I need to use the Mac OS X Finder to access platformio.ini

Any ideas why?

Thanks !

Which IDE are you using? Can you supply a screenshot?

I was Atom. I deleted the folder (generated with the IDE) and started with an empty one.
It regenerated all the needed files