I am on this platform from last 1 month but I had never experienced that musing downvote on answer after upvoting the answer.byt you have done a mistake in a question if you had a question like why does musing decrease the voting power as the day passes,because we can have proper answer for that as the day passes the upvoted we get from musing community is slightly decrease from the original upvote is due to his voting power manupulated.
Musing is a platform where we have to write answer and musing community upvote you n by the musing is a big website and everyone are working on it till today I had never experienced bad thing about it