After the last update (8.5.6), my header is showing differently on pages versus posts. On pages, including my homepage, the logo is to the left (as per my preferred setting). However, on posts, the logo is showing in the centre. 

I have gone into Customise > Logo & Header > General > Header Layout > Header 3. I changed it to another header style and then back to 3, which seemed to fix the issue. However, once I published and went out of the Customiser, the logo moved back to the middle on posts again.