The 2D text tags in the viewer are html elements in an overlay on top of the 3D canvas. Therefore, in order to position correctly, make sure you include the css file in your header:
<link rel='stylesheet' type='text/css' href='https://viewer.shapediver.com/v2/2.23.0/sdv.css'>
If that doesn’t solve your issue, make sure your css stylesheet does not override any additional styles associated with ShapeDiver (by using !important for example).
I have created a page with your model without issues.