While in designer mode, after switching to another tool from Part Shape tool, the grid manipulator "sheet" remains in place even after switching to another tool.
1-Use Part shape tool
2-use the manupulator grid to change a parts shape
3-change to another tool
4-grid sheet remains in place
Dev Notes: Holding down left mouse button and dragging to reposition the end of a fuel tank and then press and release the right mouse button appears to cause this issue every time.