Post and page permalinks return 404, others work fine

I made a clean install. After I imported demo content, pages were working normally. Then I replaced/deleted some content, made all pages with portfolio, installed a few plugins… Then I wanted to make a page, but it seems although the permalink is correct, the page is not found. Even if I click the “View” button in Admin panel, it returns the same error.

– Resetted permalink structure several times
– Checked and reset htaccess (it was already clean)
– Disabled all plugins
– Tried with basic themes: 20, 21… still same

Nothing worked so far. The issue is with pages and posts.

Theme: Suffice (Theme Grill)
Plugins:
– Chaty
– NextGEN Gallery
– Page Builder by SiteOrigin
– SiteOrigin Widgets Bundle
– Suffice Toolkit

I am not new to WP and have some PHP/MySQL skills. Worked with some WP sites, never encountered an error like this.

The page I need help with: [log in to see the link]

 

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