Welcome aboard to the QuickBooks Community. It would be my pleasure to lend a hand with your concern about the certification in QuickBooks.
Once you get disconnected from the certification, you can still go back on training by going to the ProAdvisor tab of QuickBooks Online Accountant.
For your visual reference, please check this out:
If you're unable to continue the certification, I recommend contacting ProAdvisor support through this link (go to the Support tab):
Please don't hesitate to come here if you need further help regarding the certification. The Community is here to ensure your success.