Page with shortcode only works for Administrators; other roles see “Page not found” (404)

I have a WordPress page that renders a photo wall (shortcode from a custom plugin). For users with Administrator, the page loads fine. For users with a custom role Colaborador Intranet (and other non-admin roles), the exact same URL returns “Page not found”. I need to understand if FluentCommunity/FluentAuth is blocking access and how to allow viewing for logged-in, non-admin users.

1. Is there any global FluentCommunity/FluentAuth setting that blocks non-portal pages for non-admin roles, even with “Portal Access = Everyone/Logged In Users”?
2. Are there hooks/filters in FluentCommunity that intercept all front-end requests (e.g., template_redirect, parse_request) and may cause a 404 if the role isn’t allowed? Which ones could I disable/bypass for a specific slug?
3. What’s the recommended way to whitelist certain slugs, so they are accessible to any logged-in user, regardless of portal/spaces rules?
4. If ?fcom_action=auth is the recommended login route, what’s a safe redirect URL that won’t result in 404 when the role isn’t part of the portal?
5. Any known conflicts between the “Community URL” and custom slugs (even if different) that might explain a role-dependent 404?