Hi @bellaporter, 

Welcome to the Community! Thanks for sharing your question with us! 

Do you mind sharing if you’re trying to save a block in the old vs new template editor? Or are you going back and forth from the old to new template? It should be noted that any content saved in the new editor will not be available for use in the classic editor. Additionally, I’d recommend checking out our documentation explaining how our saved blocks work in both templates  should give insight into what should be popping up, or not, and where. 

Finally, I’d also suggest testing this with another block to as well, saving a block in one version or the template and adding it another template, while also ensuring that you didn’t save a block in a different Klaviyo account, in case you have multiple Klaviyo accounts.

Thanks for participating in the Community!

-Taylor