This issue seemed to solve itself while I was creating this support topic, but I thought I send it to make you aware of it.
I’ve just added a new page and when I “Add a Section to Get Started”, everything seems to revert to “classic”. In the layout window, the lines above and below the new section say, “add classic section”. There was no option to “add a section” (i.e. non-classic) Within the edit panel of a section I’m only able to “add a classic row”.
I have other pages that say “add a section” and “add a row”. I don’t know what I did to have these things default to classic on a fresh new page, nor do I ever care to add a classic section or row.
What was strange is that the edit panels for the section and row appeared to be the new versions, not the classic.
For some reason, as I was typing this ticket and looking back and forth at Cornerstone for the new page, the word “classic” disappeared from the layout form and within the section edit area for the “add a row”.
So I think these were non-classic sections and rows right from the beginning, but the word “classic” was there nonetheless, and it through me off.