John, this issue can be fixed by rebuilding the API permissions table. You can rebuild by using one of the following methods
Shell-Based:
SSH to your server and navigate to Mumara root folder, then run the following command
php artisan rebuild:permissions
Web-Based:
Open the following URL
https://your_mumara_domain.com/execute/command/rebuild:permissions
Note: Replace your_mumara_domain.com with your own Mumara domain.