Hi @uhokaysure ,
Please reset the password again with KB: https://kb.vmware.com/s/article/2147144
Post resetting the password and before reboot, Run below commands:
pam_tally2 --user root --------------------> If number of failures are huge, Then reset the root account or unlock it
pam_tally2 --user root --reset ----------> This will unlock the root account
Hope above helps.