hover is broken on an orphan node

[micahstubbs]

hover is broken on an orphan node that is newly added.

as reported by @Tav0 in this PR https://github.com/visjs-community/visjs-network/pull/50/files

here it is a gif of the issue. (master branch)

[micahstubbs]

will try to reproduce this bug using this example http://127.0.0.1:8080/examples/events/interactionEvents/

[micahstubbs]

ok, so I took the modified example from the PR https://github.com/visjs-community/visjs-network/pull/50/files

[micahstubbs]

I'm not able to reproduce the bug - when I mouseover or hover over the isolated or orphan node, I do see the popup http://127.0.0.1:8080/examples/events/interactionEvents/

[micahstubbs]

@Tav0 curious, can you tell me more about when you see this bug?

Could you perhaps add another example to the PR that will show the bug if the fix is not present?