The winforms WebBrowser Control uses the code of ancient Internet Explorer, which means it is far from perfect.
And it inherits its settings from Internet Explorer.
The page you're interested in heavily relies on JavaScript, e.g. it needs JS enabled to generate its menus.
So the first thing to do is navigate to that page using Internet Explorer (not Edge!).
It may fail, e.g. because you did not enable JavaScript.
And when it does load, it will tell you there is an error (missing semi-colon) in some JS file, something more recent browsers aren't unhappy about. When I test WebBrowser with your page, it does show an error dialog, clicking OK is sufficient to show the entire page.
Yes, it does give
Concurso {{resultado.numero}} ({{resultado.dataApuracao}})
rather than
Concurso 5792 (02/03/2022)
I would attribute that to it being ancient technology, something most websites don't support anymore (and that is why IE suggests you use Edge instead).
My suggestion: forget about WebBrowser, and have a look at CefSharp, which is Chromium based and pretty much up-to-date AFAIK.
:)