As a project responsible I want that my supplier users in their project on a common instance see that links towards my internal projects on the same instance where they do not have access to exist.

Currently users can only see links towards projects where they have access. Those links have all the necessary and helpfull details like the Summary or Status. Links to projects without access are simply not shown for those users.

Big development projects (2000+ Devs) include often external suppliers who are not allowed to see everything. So a network of projects with linked issues exists. One project for demands, one project for development tasks, one for budgeting, one for outsourced tasks, etc.
A supplier should not see any details of a link to an issue in a project without access. Still it is necessary to see that there is a link. As projects represent broader topics, it might show that a test was generated, or budgeting is in progress. Simply because the link shows something like "BUDGET-1234 (no access)".