Keep getting free account registered without login

Since I am testing free membership registration, I notice once in a while I see someone else registered without the last login date registered. Don’t know how someone could do this as I have set it to enable login right after the free membership registration. Here is the text format of two registrations in the member display area:

80 test4897288 [email protected] free membership 2023-06-17 active 0000-00-00 00:00:00
79 test12986748 [email protected] free membership 2023-06-17 active 0000-00-00 00:00:00