🍒Panel: fix adaptive opacity not reacting to maximized windows

The mode "TaskManager.RegionFilterMode.Intersect" checks if two regions overlap, so the additional +1 is required.

BUG: 488736 FIXED-IN: 6.1.1

(cherry picked from commit 08637d60)

Co-authored-by: Fushan Wen qydwhotmail@gmail.com