In addition to the problem I described, there are other problems as well. When I try to create a different user, it gives an incorrect password after saying create an account. But in the admin panel, the account appears to have been created. When I try to log in to the newly created account, the password is incorrect. After getting these errors, I cleared the cache of the site and did it again, but nothing changed.

After creating a new user, we can log in and out of the account over and over again without any problems. 

But when we try to log into the account again after saying "I forgot my password" to a system that gives a disabled the mail() function error, we see an incorrect password error. Although the correctness of the password and username is certain