Plotly seems to break Latex rendering via MathJax in Nbconvert's HTML output. See for example https://github.com/plotly/plotly.py/issues/515 and https://github.com/plotly/plotly.js/issues/1937. NbConvert appears to rely on Mathjax configuration option skipStartupTypeset: false (the default) for Latex rendering and it doesn't call MathJax.Hub.Queue() or MathJax.Hub.Typeset() explicitly. I did some analysis:
Plotly sets the option to false:
MathJax.Hub.Config({messageStyle:"none",skipStartupTypeset:!0
And then uses the MathJax.Hub.Queue() to render only a particular DIV element, effectively disabling MathJax from other parts of a document. Can NbConvert() be made to call one of the typesetting methods from MathJax?