Steps to reproduce:
Go to Dashboard, press Edit Dashboard.
Try to resize widget, i.e. enlarge it to the left side or upwards.
If you release mouse earlier then 50% of cell widget is not resizing or leaves unresized, but jumps toward that side you tried to enlarge it.
Also, when trying to reduce size, it reduces from opposite side.

Another problem appears when user scales widget to the right or down. Not whole cell is highlighted to show supposed widget size.

See video: https://www.screencast.com/t/o26YwZ0x