Email received and Email open = 0

Hello there,

I had a bit of an issue.
We create a ghost blog and activated a newsletter.
The newsletter is received, opened but the dashboad on ghost does not changes.

But the number on the top of his profil does not change as they should :
11

We did follow a tutorial again to activate some settings on mailgun, but still nothing.
Tutorial : https://help.mailgun.com/hc/en-us/articles/360013191513-Open-Tracking-Troubleshooting

Do you have any recommandations there ?

Sincerely,

Newsletter is sent, opened and read by the person.
22

What you did on mailgun also :
CNAME as been done too