Events which are present in VIS : hoverEdge and blurEdge are missing in anular-visjs directive list and ignored . Example from source code
var networkEvents = [
'click',
'doubleClick',
'oncontext',
'hold',
'release',
'selectNode',
'selectEdge',
'deselectNode',
'deselectEdge',
'dragStart',
'dragging',
'dragEnd',
'hoverNode',
'hoverEdge',
'blurEdge',
'blurNode',
'zoom',
'showPopup',
'hidePopup',
'startStabilizing',
'stabilizationProgress',
'stabilizationIterationsDone',
'stabilized',
'resize',
'initRedraw',
'beforeDrawing',
'afterDrawing',
'animationFinished'
Adding them to list fixing the problem