Multisite won’t apply changes on settings

Hi

I have used multisite 10-ish years and now I did add a new domain and site on my install. I’ve configured name servers to Cloulflare and setup SSL. With SSL I had some problems, but now it seems to be fine. I’ve got now 3 sites install from which the new one is not working. What so ever setting I change, they do not apply. First it seems that I can do changes, but when refreshing the backend page, the previous settings are back in use. F.ex. theme is seems to be changed, but it is not after a refresh. Similar thins with all other settings on this new site. Settings just won’t apply.

I did found out that when clicking to a page in the front end, the theme changes althought I have not pick that theme to be used.

There is no error messages in the PHP error log. Time to time the backend gives “The Link You Followed Has Expired”. I did check the upload settings and I cannot see anything wrong in .htaccess. But because All other sites are updating an running good and smoothly, I think this is not about that.

Because I cannot figure out what is wrong, I wish to have help.

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