Hi @leeH! Thanks for joining the monday.com community
We do have an automation to create an item in one board when an item is created in another board and link them together automatically:
I will say this automation works best when paired with a form so that the item is created with all of the details already filled in. Whenever you manually add a new item, the item is technically created whenever you enter the name and click add or hit enter. This means that the automation would trigger with just the item name and not pull in the other details for the new item in your other board.
With that being said, I would recommend using one of the other similar automations available that would be based on a different action trigger:
All of these automations will automatically add in a link between your items using the Link to Item column. I also recorded a short video to show you how you can use this paired with a Mirror Column to automatically fill in the mirrored data as well:
Using the Mirror Column with a Link to Item Automation
Let me know what you think!