Hi @Lucaaa, I have the same problem....
this is Apple answer:
Hello,
Thank you for your
question. My name is Steven and I am glad to assist you today.
In order to submit a
new Apple Developer Enterprise Program enrollment, the proposed Applicant will
need to use a different Apple ID email address than the one that was previously
used by the Account Holder.
But I need my old account and not to create a new one