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Answering my own question…
It is not some WordPress plugin – but Chrome (80.0.3987.87) which is converting my linked stylesheet to inline style.
And I assume this is because I have the linked stylesheet within the HTML document body, instead of within the head. This was not supported at all in HTML 4, but is allowed, though not recommended, in HTML 5.
Firefox 72.0.2 appears to fully support linked stylesheets within the body, but Chrome converts to inline.
I worked around the problem by using <style>@import url("my-stylesheet");</style>
And, finally – it mattered – because I was using @media to control style when printing, and @media is not available for inline styles.
>> And, finally – it mattered – because I was using @media to control style when printing, and @media is not available for inline styles. <<
Thanks. Someday, if I remember that, it might save me some considerable grief. HOWEVER, your plugin should be enqueuing stylesheets correctly, which puts them in the header.
