After Migration, No Admin Privileges

You might want to check privileges of your admin user. Here’s a tutorial on how to set permissions in the database for the user:
https://www.wpbeginner.com/wp-tutorials/how-to-add-an-admin-user-to-the-wordpress-database-via-mysql/

If for some reason you can’t get your user permissions right, try creating temporary user with admin permissions using tutorial above and then login and set admin role for your existing admin user.

^V