Hi @franva and welcome to the community.
This doesn’t seem to be related to Netlify CMS. Looks like this is the Gatsby’s code that’s generating the directories:
Can you confirm you’re using Gatsby? Can you share the repo/a scenario these directories are created?
If using Gatsby, I recommend gatsby-plugin-netlify-cms | Gatsby as a setup guide.
I would also try asking in one of Gatsby support channels.