emClient doesn't show all emails in inbox

Hello,

I run eM Client 8.2.1478 (856f724) on my Mac systems.
Unfortunately eM Client doesn’t show all emails in inbox.

Today I was waiting for emails of two clients and they didn’t show up on eM Client. Since one client sent the email twice, I was curious and checked in my email providers webmail interface.
On the Webmail clients, I finally saw the email of my clients in the inbox folder.

Why didn’t they show up in the inbox on my eM Client?

Cheers

Niels