Less performance oppening connection from 5.x to 8.x driver

[JAVIER NIETO]

Hi,
I'm migrating a .Net WinForms application that use Mysql from 5 to 8 database version. I changed the driver from 5.1.4.0 to 8.0.24. After that, we notice lower performance opening connections. In fact, our measures are 170/190 ms vs 400/500 ms. We didn't change the code but only the driver. It's not too much but enough to worry about.
We are using .Net Framework 4.6.1 and Visual Studio 2015. I read in mySql documentation (MySQL :: MySQL Connector/NET Developer Guide :: 2 Connector/NET Versions) that the .NET Version Required for this connector is .Net Framework 4.8 but in any case, I can see reference support for 4.5> in the nuget package.
I coded a little program isolating the connection in order to avoid other distractions and I have been trying a few things:
- Change the to .Net target framework to 4.8.
- Change the mysql connector to 8.0.30 version.
- Change the mysql connector to 8.0.11 version (.Net Framework 4.6.1 compatible).
- Repeate the tests with Visual Studio 2019.
- Deactivated temporally the SSL support on the server. That's reduced the connection time in 100 aprox… but the mysql 5.1.4.0 connetor is being up to 200ms better.
- Change the mysql connector to 6.9.2 version.
- Server is setting skiping name resolution.

We didn't notice better performance in any case, except for the reduction where you turn off the ssl support.

Where is the problem?, What I'm doing wrong? Can I do anything?

Thanks in advance