Try accessing the console using the shell of your pvm node. You can do that by using.
lxc-attach --name 100
Change 100 for the number you have given to your CT.
This lets you access the console of your container without using credentials.
The password user of the CT should be root and the password the one you have given in the process of setting it up.
However, I have to admit, I went straight for the lxc-attach --name 100 as I was feeling lazy 