Can't Custom Mediation Adapter serve ads?

[jongsu253]

Hi, I'm working for an Ads SDK company.
I hope our sdk will be mediate through Admob.
So, I implemented the mediation adapter according to the official guide and then checked the product by using the Mediation Test Suite.

However, even though the information about the Custom Event is correctly recognized, the adapter implemented by New API did not call the initialize method. So Admob ignored the correct response to the load request because the Adapter settings were incorrect.

So I implemented and tested the Adapter using the Old API in a similar way, and it worked well. I wonder why this is happening.