I have escalated your issue to the Comcast Team available to these forums. Check back often for a reply in this thread from a Comcast Official Employee.
I tried to duplicate the issue you reported but am still able to see past videos. Can you please make sure you have the most recent update?
If you do and are still having this problem, I'd like to investigate further. Can you please verify your first and last name, and the phone number or account number associated with your services in a private message?
To send a private message click on my name "ComcastChe", then click send a message.