Selecting a line of text and turning it into a header (ctrl+1) removes the selection highlighting but keeps the text selected. Additionally turning text into a header also moves the position marker to the wrong place (visually).

As a result e.g. the action of creating a header then pressing enter replaces the header by an empty line.

Se screencast below for procedure and illustration.
https://www.youtube.com/watch?v=7OtpP5iS2uw

Reproducible in Chrome and Firefox

Version: unspecified
Severity: minor