The problem start after I transfer the site to https.
I followed this tutorial : https://kinsta.com/blog/http-to-https/
Herre what I did:
1) My hosting company installed the certificate on the server
2) I did Redirect HTTP to HTTPS by editing the .htaccess file
3) I Updated Hard-coded HTTP Links using the plugin Better Search Replace
4) I didn’t Update Custom Scripts and External Libraries
5) I did change http to https in the wordpress general setting.
My hosting company told me that they use http/2 for their site using SSL certificate. Maybe it can change something with our problem …