@rezocharly by default it shows unseen emails. Just checking there are unseen emails in the root of the inbox you are showing?
It helped me to write a little email program based on the code example of mscdex . Put it e.g in em.js in email folder and run it with
node em.js
If you add
debug: console.log,
to the imap config section in the em.js, you get a good overview of what is happening.