In the K2 user profile page the description field is 'locked'. JCE is not activated and leaves a plain text field in which you can't type. Editing an article is fine, like other places in Joomla where there's an editor. And it only occurs to registered users or any other usergroup than the superadmin.
See also: https://www.joomlaworks.net/forum/k2-en/57078-users-can-t-edit-their-profile
Joomla 3.9.24
JCE 2.9.2
See also: https://www.joomlaworks.net/forum/k2-en/57078-users-can-t-edit-their-profile
Joomla 3.9.24
JCE 2.9.2