That’s this bug: Blank lines at start of note skipped by Up arrow
Basically browser only renders the newline when there’s an existing newline at the end.
We’ve investigated this issue before, and it’s a browser behavior that we need to do extra work to work around, not because we did something wrong. It’s quite some work, and to properly fix it, we need to backfill everyone’s existing content too.
Sorry for the delay in fixing this!