Impossible to import

Hello.

It’s impossible for me to export my settings. I test various “master” website and various “child” website, never i can import.

For exemple, i follow this step :
– on master website, going to “Manage Settings” and “Export settings”. All is checked. Click on “Generate export”. 3-4 seconds and appear in input zone. I click on copy button. “Copied!” appear.

– on slave website, i past in the import zone, i click one the button, “The settings have been successfully imported” appear.

I refresh and……. nothing Oo

What can i do for resolve. Big thanks