At the moment, sysadmins/admins cannot see a private plan unless they have been explicitly granted access. It would be desirable that admins have access to all plans.
This is to allow sysadmins/admins to see Private Plans for cleaning up purpose, for example when the said use has left the company.
You can use the following DB edits, noting these were written in PSQL update per your DB requirements
Using the Desired plan ID and username insert the 0 and 1 permissions into that plan with the following for the user