OK, I confess! It has been a while that I have not used page layouts and especially now when we have got SPFx, and other nice things.
I created a page layout using Design Manger (SP 2013 :(). I have published the page layout, however it does not show up in: Page layouts and site templates.
Of course, nor in the Ribbon or when I create a new page.
Both HTML and aspx are present in the Master Page Gallery.
What am I missing or have forgotten? 🙂