Referrer Policy: Ignoring the less restricted referrer policy

I am being flooded with messages of the form:

Referrer Policy: Ignoring the less restricted referrer policy “no-referrer-when-downgrade” for the cross-site request: https://www.googletagmanager.com/gtag/js?id=

I cannot find any specific documentation of this message or any concrete suggestions of how to clean it up. I am merely referred to https://web.dev/articles/referrer-best-practices, which is not enlightening. There is nowhere in the web page source, which I do not own, where referrer or referer are present. This “help” page does explain why Firefox is issuing the messages:

" Firefox The default is strict-origin-when-cross-origin .
Starting from version 93, for Strict Tracking Protection and Private Browsing users: the less restrictive referrer policies no-referrer-when-downgrade , origin-when-cross-origin , and unsafe-url are ignored for cross-site requests, meaning that the referrer is always trimmed for cross-site requests, regardless of the website’s policy."

But that does not explain what change should be made by the site administrator to get rid of these useless messages. Specifically if nothing in the code that the site administrator has control of explicitly asks for "no-referrer-when-downgrade” then who is issuing these requests. And if it is not from code owned by the site administrator why is Firefox complaining to the site administrator and the end user rather than the author of the code issuing the flawed requests?