New user cannot be found in search by admin

Hi guys
Now when members sign up I cannot see them by searching for them using admin account
To replicate the issue
Sign up using test account
login to backend activate the new account
login with admin account, try to search new user created, it cannot be found by admin in frontend of site, but seems to be registered correctly in backend

.........update...............
Seems that in backend I have ban the user then unban the user to make the account work correctly.


Kindly advise
Thank you