This requires you to point the mouse at "contacts" (that is, you use it to search for small things like the cloud below)

You point the mouse to a small downward arrow on the right of "Contacts" and just click it. Then "avatar display", "name display" and "list display" will appear.

Just display this "list" with the mouse, and the third one is "display refresh information". If there is a small tick, just click it.

In the column of "Personal Settings/Personal Data", remove the check before "Always show personalized signature" and confirm.