Sentence highlighting not working on articles with math formulas. Split from T229906.

Using production wikis:

Using https://pt.wikipedia.org/wiki/Special:ContentTranslation?title=Special:ContentTranslation&campaign=contributionsmenu&to=pt&page=Tensor+product&from=en&targettitle=Usu%C3%A1rio%28a%29%3ATestpitanormal%2FProduto+tensorial

• Loading existing translation - doesn't show highlighting
• Creating new translation - doesn't show highlighting

Using different language pair with the same Tensor product (en to ca)

• Loading existing translation - doesn't show highlighting
• Creating new translation - doesn't show highlighting

Using any different article with math formulas:

• Loading existing translation - doesn't show highlighting
• Creating new translation - doesn't show highlighting

Conclusion: It doesn't matter the MT engine nor the language, any article that has math formulas doesn't have highlighting available.