Unable to post this as a comment, but the indentation is likely part of one of the active modes (probably lisp-mode based on your description).
You can do M+x describe-modes to see which modes are active.
This answer provides some background on the history of the common lisp commenting style https://stackoverflow.com/a/6365579
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The standard key for this behaviour is M-j. It is bound to indent-new-comment-line by default but, depending on the buffer, may be bound to some other mode-specific analog. These commands take care of indentation, and also comment continuation when you're inside one.
In programming modes I make RET do whatever M-j does:
(defun my-coding-config ()