I see your role has all capabilities from ‘posts’ and ‘pages’ groups. It’s enough to edit any post or page, in general. You need to check if your role or/and user does not have any additional restriction, may be set accidentally or by other plugin.
1) try to deactivate User Role Editor and re-test;
2) try to deactivate all plugins and re-test.
In case if restriction was added by some plugin, activate plugins back one by one and make another test in order to isolate a reason.