Repeating username in patient portal

Hello,
I found out that while generating username and password for patients for patient portal usage by the patient, the system keeps generating the same username for different patients in the openemr system though the passwords are different for which the password is editable or changeable but the username is not.
This has led to the inaccessibility of the patient portal by the patients with such issues.

Please what can be done.

I am using openemr 5.0.1 with patches 3

Thanks