I think the decrease in upvotes from musing is due to increase of threads lately. There are so many unique questions and answers on musing that deserves to be rewarded and if musing must reward at least 80% of the contents produced here then it has to reduce its voting power. The lower the voting power the lower the upvote.

Again, once the voting power is drained, upvotes naturally decreases too until voting power recharges and I doubt musing has enough time to recharge their voting power as they are always rewarding great contents here.

I must say they are doing a great job.