blocked pages still blocked after login

Hi,
When anyone logs in by visiting a blocked page, nothing happens on submit. The form stays there and no content access. However, you can access admin pages.
We don’t use a Login page, as such. Just the form on blocked pages.
The member setup has been in place and working for years (thank you), but now not working. No major changes have been made to the site in the last couple of days other than plugin updates. WP-members was one of them, I think.
Thanks.

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