It’s quite normal for Mediation revenue not to show up as you’re earning the highest revenue for your inventory via other channels.
Ezoic gives you access to Ad Manager which pushes up prices for your inventory by giving you access to a large range of networks that will often out-bid partners on the original setup. If you are not seeing any Mediation Revenue, then your Ezoic Ad Partners are winning against your Mediation setup.
To ensure your Mediation is set up correctly, please feel free to go through the following support article - https://support.ezoic.com/kb/article/google-adsense-and-the-mediation-app.