Depend on your location, may be your PNETLab can't update the time automatically then your PNETLab can't not download Lab or Login by Online Account.

Follow those steps to fixed:

Step 1: Go to Console screen of PNETLab and login with root account.

Step 2: Change your time Zone to UTC by command: 

timedatectl set-timezone UTC

Step3: Edit your time by command: (The time is updated automatically you don't need to change just copy and pates)

date -s ' '