Bug in ACR v11.1.0.112 @ Win10x64 with WB tool when selecting a region in B/A View

Bug in ACR v11.1.0.112 @ Win10x64 with WB tool when selecting a region (left mouse button press and drag mouse pointer to select a rectangular region to perform WB) in Before / After View : when B/A View is either in "Before/After Left/Right" on in "Before/After Top/Bottom" state I can _NOT_ see the rectangle (showing area selected for WB operation) being drawn/displayed while I am dragging the mouse pointer while pressing the left mouse button... in 2 other states "Before/After Left/Right Split" &  "Before/After Top/Bottom Split" no issues