For example if I use the Insert tab and then click in the document, the Ribbon goes back to Home. How to make the Insert tab stick, that is for Word to stay on the last tab I have used?
The issue appears when you clicked "Collapse the Ribbon" or the Word is set up with it. It is not a bug, but rather something a novice might not know. To solve it, go to the right of the ribbon and pin it-there is a small pin that you click. Or right click and uncheck "Collapse the Ribbon".