When I enter a saved service in time activity, why do some of them then automatically duplicate in "description" and some don't?

Allow me to share some information on why items are duplicating in the description field, James222.

If you have entered some details on the description box when creating the item, this will show when you use the service.
 

To ensure your services will not duplicate on the description field, I'd suggest going through the items and deleting the description from there. Here's how:

1. Go to your Products and Services section.
   
2. Locate the service item and click Edit.
3. Remove the details from the Description box.
4. Hit Save and close.

Additionally, you can visit this link if you need help in managing your items as well as tips on how to enter multiple hourly rates:

Set up and track your inventory in QuickBooks Online. 

Enter a single time activity timesheet.

Ping me in if you have additional questions about QuickBooks items. It's my priority that all of your concerns be addressed. Have a good one!

Hi, James222.

Hope you're doing great. I wanted to see how everything is going about duplicate items on the description. Was it resolved? Do you need any additional help or clarification? If you do, just let me know. I'd be happy to help you at anytime.

Looking forward to your reply. Have a pleasant day ahead!

That told me what I needed to know. Thank you.