Draft URL mangling in Safari iOS

I’ve got a draft piece I tried to share with some readers.

It’s located at A Calendar for the Shop — Write.as but when I select “copy” from the share menu in iOS Safari (18.4.1), I get A Calendar for the Shop — Write.as for a link instead (no .md extension) which doesn’t render correctly. If I select all in the URL bar and copy, I get the .md version, which does render correctly.

Help?