RE: Assign owner change tasks owner to me
Hi Emma,
After assigning a contact, the related tasks are also been assigned, which is by design. Because the Assign behavior of the 'Contact to Task' relationship is locked to 'Cascade All'.

So if you want to change the Owner of these tasks for you, then you need to search out the assigned task records first, and then assign them to you.
Open Advanced Find, look for Tasks, select Regarding equals the assigned contact.

Click Results, then select all and click Assign Tasks. Assign them to you.
