Bug on the massive registration of customers with the store closed

We are finding a bug in the registration of customers by bots en masse. It is happening to us in several different Nopcommerce and different versions.
So it seems initially it is not a recaptcha problem since in the last Nopcommerce that we have detected this "bug", even with the store closed, without the option to register, hundreds of new customers enter.
The version of this Nopcommerce is 4.10
This causes poor customer management, but the main drawback is the size of the log files, the exponential growth of the database and its impact on loading speed, which become very slow stores.
We would like to know if anyone has found a solution to this, as otherwise we are almost decided, unfortunately, to stop using NopCommerce and start with another CMS. It's a shame because after more than 10 years and more than 30 managed Nopcommerce ...

So you've set "Registration method" to "Registration is disabled" at the "Customer settings" page. And you still can visit the registration page and register. Please confirm

Could you please provide a complete list of steps to reproduce the issue?

Please confirm that these new customers in admin area are not "guests"

Hi Andrei.
The customer registration attack was stopped. We do not know how they could have occurred, since the store was closed and there was no access to the registration form.
On the other hand, the registration of invited clients is constant, producing several registrations per minute (about 5000 daily registrations).
We understand that this activity is unusual, especially for recently created websites, so we would like to know if there is any way to optimize this traffic.