Firefox / OpaqueResponseBlocking

Hi all,

I have a website (www.mydomain.com) and another website with data / images (data.mydomain.com) ont he same server under Plesk.
All works fine with Chrome and Edge but with Firefox, image don't displayed.

In the console, there is: A resource is blocked by OpaqueResponseBlocking, please check browser console for details.

I try to change headers like that but no effect.

Apache
Header set Access-Control-Allow-Origin "*"
Header set Access-Control-Allow-Methods "GET...

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