Major version upgrade to MySQL 8.0 from 5.7: Fails validation process with error "Usage of removed functions" but it doesn't show any detail on what functions are failing.

Question

I am trying to upgrade my Azure MySQL from 5.7 to 8.0 version. I am following the current guide:

https://learn.microsoft.com/en-us/azure/mysql/flexible-server/how-to-upgrade

The problem is that it doesn't specify which functions are failing or the objects than are causing the issue, and it's very difficult to check all of then reading the document of deprecated functions.

Is there a function or logs to find out more details about this problem?

Thank you very much in advance.

Regards.