Hello, I'm posting this to give a hint on the problem showed up on the tickets https://www.akeeba.com/support/site-restoration/37003-restoring-database-access-denied-you-need-at-least-one-of-the-super-privilege-s-for-this-operation-1.html and https://www.akeeba.com/support/site-restoration/36772-restoring-database-access-denied-you-need-at-least-one-of-the-super-privilege-s-for-this-operation.html
I hope these infos can help you in debugging since I've already solved changing the PHP version:
the issue was happening when the selected PHP version was 8.1.3; switching back to 8.0.16 I was able to restore the database.
This was the environment as you requested in the previous ticket:
Mysql driver: Mysqli
DB server: Percona Server 5.7.32-35-log - Percona Server (GPL), Release 35, Revision 5688520
PHP: 8.1.3
Provider: Aruba, italian shared hosting company (imposed by the client)
I don't know at which point of restoration the error occurred since I don't have access to db logs, but it seems was happening at connection (no percentage of restoration was reached, and the error was quite immediate).
I hope this helps,
regards.