Hi Spencer

Thanks for the question and for providing a thorough (and high quality!) resource on your experience. I'm currently looking into whether this is intended behavior or perhaps a new bug we're experiencing. While I wait for more info I wanted to get a response to you so you're not waiting too long. Keep an eye on your inbox for a follow up!

Hey Spencer 

Following up. I've gone ahead and filed a report with our engineers. To set expectations they have to rigorously prioritize tasks so I am unable to provide a turnaround time for when you could expect this to be fixed. I will be sure to add a post to this thread when I hear back.

Thanks for taking the time to share this issue with us! Feel free to follow up with anymore questions.

Hi there has this been resolved? 

I'm sharing a published document and none of the thumbnail links work for me either. 

No response yet Tim. I keep checking back. I'm still really hoping to use this feature. It will for sure make or break maintaining my subscription.