html tag error when export x3d

I'm using py2.7 and VTK8.1 and mayavi in jupyter notebook on mac, x3d output can be shown properly in notebook cells but once I export notebook to html, the order of html tags in x3d section would change, the ending tags are at wrong position.
Tags can be closed normally until x3d->scene, as is shown below:
But inside scene, when the tags should be parallel:
the output html treats them with different level:

Replace the counterpart in html manually will solve this question.

If I use mlab.savefig("xxx.x3d"), tags will be closed with /> at right place:
`


`
(And that is actually what happened to output html of jupyter notebook), but when I import this to x3d viewer, like this chrome extension(blender does not work on my mac )
https://chrome.google.com/webstore/detail/x3d-viewer/hjglnfapllnalfggjeeieeobhjmieail?hl=en-US
the situation becomes the same as wrong closing tag positions.

On the other hand, the x3d output of first cell below can display normally in exported html:



Is this related to mayavi or x3d itself? Could anyone give any clue? Thank you very much!