Lost in translation
Copy and paste via the clipboard from the browser to a screen mintty terminal session, non-breaking spaces, (U+00A0) were turning into ASCII spaces (U0020). (But also to Windows ‘cmd’)
I couldn’t see! Not hiding in plain sight, but not quacking like a duck, either. ‘curl’ spoke the truth, saving to a file.
The culprit is the browser, clipboard, screen or mintty?
Apparently this is a 15-year known browser bug. A #knownbug. https://stackoverflow.com/questions/47135608/no-break-spaces-are-turned-into-normal-spaces-after-copy-paste
echo -ne '\xa0\x20' | hexdump -X
is your friend.
Me atBack to WYSInotWYG