Presentation page no longer working

Hello Zed,

prezentation page is not working on my website since yesterday.
On Monday Jul 7 night it worked without issues, when I started working on the web on Tue morning there was Blog page instead of Presentation page. I read through the forum and older threads and Im convinced all is set correctly:
Presentation page enabled
Show posts on presentation page disabled
Reading set to latest posts.

I would very much appreciate your help or advice.

Thank you