Emacs often changes the behavior suddenly and drastically. Recent surprise to me was that role of ctrl-j (newline and indent) and ctrl-m (newline) switched out of the blue. I don’t understand the developer’s sense of changing user interface of a multi-decade years old software. But luckily, emacs has very powerful customization ability.
Adding this line reverts the key bindings back.
(when (fboundp 'electric-indent-mode) (electric-indent-mode -1))
I appreciate this post