I have the same problem with the static pages. When I started I had the “default permalink structure”, and I could write and save one page.
Then I started fiddling with my permalinks, and finally did get them into a form that pleases me (or my eye, rather). But now only the first statc page works. Whenever I try to write and save a static page, and then go to my blog, and click on it, I will get a “page not found” error.
I know, most certainly, that if I go back to the original permalink structure, I will get the static pages working, but I so much like my permalinks now…!
The URI to my blog is https://www.squash.nu/blogi