Hey @jmum I think I know what it is.
I’m on Linux but I think it’s safe to assume that this is what’s causing it in Mac.
If you go to Obisidan Settings > Hotkeys > Delete Parragraph
This shortcut is causing conflicts for what you want to achieve.
All you need to do is press on the "x" to remove this default shortcut
Now it should work without any issues
Edit:
I’m the worse I skipped and didn’t read the fact you already tried this
This should have worked, just in case, it’s worth trying to reload obsidian
to reload Obsidian do cmd + r
If that doesn’t work then it could be a bug for sure
Best of luck!