Vital CRM
How to set up the editing permissions for customer managers' tasks?

Click on [Settings > System Settings > Security > Expand Privileges], then check the box for "Allow task assignee to modify tasks." The task assignees who are assigned with tasks will be able to edit the tasks assigned to them.

[Settings > System Settings > Security > Expand Privileges > Allow task assignee to modify tasks] (Refer to FAQ)
https://faq.vitalyun.com/EN/CRM#4480