Talking to my associate, I remembered that long ago had created a user named "webmaster" with privileges on all databases.
I ejecute the following commands to restore the situation:
a) mysql --user=webmaster --password=xxxxxxxxx
b) grant all privileges on *.* to 'root'@'localhost' with grant option;
c) use mysql;
d) grant all privileges on mysql to 'root'@'localhost' with grant option;
I will open a detailed report to explain what happened to me, it seems the scripts to restore the root user does not work correctly.
Sincerely grateful for taking the time to solve my problem.