Emails not showing in folders

Hi all, hope you can help. I am using latest (8.0.2951) version of eM client, and am using it to front-end my Gmail account. I have some folders when viewed in eM cleint, it is empty, but viewing the same ‘folder’ (tag) in GMail, there are emails there. As soon as I open one of them in Gmail, it will appear in eM client, at the next refresh.
any idea what is going on?

thanks for any help!

Not sure if this will help or not, but there is a more current version available