Lasso tool not moving drawings

ok so i am trying to edit drawings in some of my frames and the lasso tool will move some but on others frames i try to edit the orange box is not appearing.

ill hover over the line work and it ives me the little plus symbol to move it bit when i try to move it an orange outline appears and the object stays put.

does anyone know whats happening???

i uploaded a video here https://www.youtube.com/watch?v=sM0c-zv-UU4&feature=youtu.be