Why PO Change Orders are automatically getting created to Cancel a Particular PO line

Summary:

For few Purchase Orders, the Change Orders are getting created automatically to cancel certain lines. When checked for these lines in the planning side, and we can see that for these PO lines the line release status is showing as "cancel". We can also see that there are no demands against these PO lines. (i) Is this the reason the line is getting cancelled?

(ii) If the Line Release Status becomes cancel in planning side, can this cancel the PO lines by creating a Change Order automatically?

(iii) If (ii) is true, then is it possible to restrict the Change Orders from getting created if the line gets cancelled from the planning side?