Steps to reproduce:
1) In an empty org-mode buffer, type a * SPC a C-b C-b C-b <RET>.
2) The buffer now has two lines, the first one "a" and the second "* a".

Expected:
3) The second line is formatted as a first-level heading.

Actual:
3) The second line is formatted as normal text.


Emacs  : GNU Emacs 26.1 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)
 of 2021-01-31, modified by Debian
Package: Org mode version 9.3.6 (release_9.4.6-544-gc5573b @
/home/user/.emacs.d/straight/build/org/)