Why The Scheduler user does not have "Administer Project" and "Create Issue" permission?

This could be noticed in next-gen projects or with new Service Desk projects, when new permission schemes are generated. It is related to role created for apps: atlassian-addons-project-access. Here you can see the details: https://community.atlassian.com/t5/Jira-questions/Project-Role-atlassian-addons-project-access-has-been-added-to/qaq-p/421651

Make sure this role is included in both of mentioned permission, or specify system user "The Scheduler"