Thank for the debug time.
The page you point is not coming from the wordpress blog. All the wordpress blog pages start by https://www.gaudry.be/photo/
But indeed, I have also to modify the author page, and I do it now :-)
The browser is cleared (cache, temporary internet files, cookies, etc.) and restarted.
I still have the warning.
I did a few more tests :
When I create a new user, I do not have the warning, but the warning is shown for any existing user (and not …