Please follow the steps given below to change the cpanel password to avoid this from happening.
1) Login to cPanel with current password
2) Goto cpanel >> Preferences >> Change Password
3) Put OldPassword and NewPassword.
4) Keep “Allow MySQL password change” checked and then click on “Change your password now”.
You should get the output :
Your password has been changed!
The following services were updated (if any):
mySQL <= important to get this (You will not see it if you uncheck “Allow MySQL password change”)
FrontPage (you will get this if frontpage is provided on the server)
5) Logout (Again important)
6) Login with new password and then go to cpanel >> Databases >> PhpMyAdmin
Now you should be able to get into the PhpMyAdmin without login Screen.