O/ and l/ result in strange characters

When I type a O/ or a o/ I get the letter “Ø” or “∅” (Unicode character U+2205), referring to the empty set.
When I type a L/ or l/ I get an “L” with a slash through it.

These both happen in Text documents.
I’m using English (USA) and have no idea where these characters are coming from.

How do I stop this!

And you get this on an empty, new writer (ODF) file not based on an old template?

BTW: Which operating system and LibreOffice version is your problem related to?

Yes, I get this even in a new document.
Mac OS.
Version: Version: 6.0.3.2
But this has been happening since like version 5.

I can’t reproduce it in openSUSE 15.1 or Windows 7. My guess: it is something about your operating system and input method. Check respective settings.

I did say this was happening in Mac OS

I upgraded from 10.12.6 Mac OS to 10.15.2 and POOF … the issues is gone!

I upgraded from 10.12.6 Mac OS to 10.15.2 and POOF … the issues is gone!