Description of the problem:
Safari browser on a mac (at least Safari 17.6 running on macOS Monterey 12.7.6) automatically / silently normalizes any string to NFC when copy/pasting into the input text box of Codepoints' Analyze, thus rendering it unusable + confusing the user about whether this functionality is bugging or working correctly.
IMPORTANT: Please note that Safari browser on iPhone doesn't have this problem (at least on my iPhone 8 running iOS 16.7.10, it's NOT normalizing to NFC when copy/pasting)
Suggestion of fix:
When the user agent is Safari on a mac, add a warning text in red to inform the user about this problem and suggest him to use another browser.
Notes:
I've tested Safari on iPhone, Firefox on Mac, Chrome on Mac, Firefox on Windows, Chrome on Windows, Edge: no other browser than Safari on a Mac show this particular problem.