I'm grateful for the update that you gave regarding your inventory item list concern, @pmorrell.

I've got additional troubleshooting steps to provide that can help fix this issue since deleting the items didn't free up the list.

Let's go ahead and re-sort your item lists to better isolate this matter. This process resolves any odd behavior in your master names list, Item list, or Chart of Accounts in the system.

Before doing this, switch to single-user mode. Click the File menu, then choose Switch to Single-User mode. Let's also ensure to update QuickBooks to the latest release to avoid issues in the program. 

Once done, please follow these steps to re-sort the list:

1. Click on List.
2. Press on Item List.
3. Hit on the drop-down arrow beside Item.
4. Select on Re-sort List. 

For complete details about this process, please see this link: Find out how re-sorting helps you with your lists in QuickBooks Desktop.

On the other hand, if doing this doesn't make a difference, I recommend verifying and rebuilding your data. This can fix any possible data-related issues on your company file.

To do that:

1. Go to the File menu.
2. Hover over Utilities and select Rebuild Data. 
3. On the QuickBooks Information window, select OK. Follow the onscreen steps to save a backup.
4. Let the tool repair your file. It may take some time. QuickBooks may seem stuck, but as long as you can move your mouse, the tool is working.
5. When the tool finishes, select OK.

After that, you can now verify the data:

1. Go to the File menu.
2. Hover over Utilities and select Verify Data. 
3. Let the tool check your file for data issues.

You can utilize this article for more information regarding this procedure: Learn how to fix data damage on your QuickBooks Desktop company file.

Let me know how it goes by leaving a comment below. If you need anything else, don’t hesitate to ask. I’ll be here to help. Have a most pleasant day!