Hi,
So let's discuss how you would do what you want. What you need is a way to bind all the values, based on what is in the Selected Dropdown1 (your employee)
I recommend that you use a Form. You can use a Gallery, but it requires a tiny tweek.
Also, while it is certainly ok to update the backend on every "OnChange" (regardless of whether its a check or not), take into account the traffic it creates, versus having the supervisor simply hitting a Save button. It's much easier to debug and have less chance of failures and problems doing a single patch versus after each change.
Your drop down should be outside the Form, because it drives the checkboxes.
We will use the dropdown1 to set the Item property of the Form, which in turn sets all the checkboxes.
Since this is a Form, it will automatically bind and create the associations of the checkboxes to the back end.
Form Item Property Code below
LookUp('New Hire Tracker.TaskTracker', EmployeeName = Dropdown1.SelectedText.DisplayName)
Now, your defaults for your CheckBox will be
ThisItem.ColumnName
Now I recommend, outside of the Form, you have a button, it would be your Save button.
In this way, your OnCheck and UnCheck do not have code.
In your Save Button, you only have to put the following code.
FormName.Submit() and it will patch the back end
So it looks like this.
Let me know if you have anu questions