Musing official account does often vote for questions but the vote value is generally lower. That is because it is much easier to write questions compared to answers.
Musing is still a new software that is just getting started. Much of its functions haven't yet been organized properly.
The curation system is no different. Musing doesn't have any proper framework yet about how it should judge and upvote questions.
Also, questions get upvotes from visitors who are viewing them. For example, I myself just now gave you an upvote in this question.
If a question writer consistently writes good questions, he most likely will get noticed by the musing curation team.