Hi @tim f101 thanks for posting in the community! It sounds like you are using the Product roadmap with Smart Containers template is this correct? 

To move the containers and items around in the smart containers you will need to first double-click the containers to enter the editing mode for Smart Containers. I've also attached a GIF demonstrating this:

For more information on Smart Containers I recommend this Smart Containers article from the Lucidchart Help Center. 

I hope this helps! Please let me know if this isn't what you are looking for or if you have any questions. Cheers!