Problem with repeats

I would say this is probably not an appropriate use of voltas. Voltas that continue across many measures like this are very hard to human musicians to follow. In theory, MuseScore can do it better, but you need to extend the voltas properly to go all the way to the repeat (double-click, shift+right arrow as many times as necessary), plus set the repeat counts in the volta properties and/or measure properties. Really, though, that;s way more work than it's worth just to avoid writing those first five measures again, and the people reading your score will thank you, too!