'Assign using active assignment rules' checkbox always checked by default

To prevent Assignment Rules from triggering automatically on every edit, disable the "Default" setting for the Case or Lead Assignment Checkbox in the relevant Page Layout.


Steps to resolve in Salesforce Classic:

1. Go to Setup.
2. Navigate to Customize > Cases > Page Layouts.
3. Click Edit next to the relevant layout.
4. On the Layout console, click Layout Properties.
5. Uncheck the "Default" option next to the "Case Assignment Checkbox" to disable the auto-check behavior.
6. Click OK and save the Page Layout.
   
   

Steps to resolve in Lightning Experience:

1. Click the Gear icon and navigate to Setup.
2. Click the Object Manager tab.
3. Select Case and click Case Page Layouts on the left.
4. Edit the relevant layout.
5. On the Layout console, click Layout Properties.
6. Uncheck the "Default" option next to the "Case Assignment Checkbox" to disable the auto-check behavior.
7. Click OK and save the Page Layout.
   
   

Note: The same steps apply to the Leads object. In the steps above, select "Leads" in place of "Cases."
Important — Additional behavior to understand:

• To force Case Assignment Rules to always run (regardless of user action), enable the "Default" checkbox AND disable the "Show on edit page" checkbox under Case Assignment Checkbox. This removes the ability for users to turn off case assignment when editing or creating a case.
• If both checkbox options are enabled, the Assignment checkbox is displayed when creating and editing a case and is checked by default.
• NOTE: Unlike the Case object, the Lead object requires the "Show on edit page" checkbox to be enabled when the "Default" checkbox is enabled.
• When Dynamic Forms is enabled for Leads, "Assign using active assignment rules" needs to be enabled from the Lightning Record Page.