Hi @seref.arikan,
Depending on your subscription plan, there is a limit to the number of production tenants you can have. If you exceed that amount, those tenants will be under a free subscription plan rather than your paid plan.
See below for these limits:
(Reference: Pricing - Auth0)
If you need to create a production tenant per customer, you might need an Enterprise subscription plan to support that requirement. This way, you can have an unlimited number of production tenants.
Let me know if you have any further questions.
Thanks,
Rueben