Hi Sergei Shibanov,
PFB my answer of your queries.
Is it possible use only first two lines for reproduce issue?
Answer- Yes
Answer - htmlString as read html from file as string and pass it, which I have shared.
Htm…...CultureInfo…ctor(String name, Boolean useUserOverride) at System...#=ziL4NRqm57bNDxY2Ik0G.#=znoi8KMY=(Boolean #=z2rwptz0=) at #=zsXwYCo8lDR2aqKE9o0A...