Like the title says, if you want to upvote something on KBin, you should use the Boost link, not the upvote button (Why? Don’t know…)
The upvote button doesn’t seem to do much, but Boost accomplishes what Reddit’s upvote did. So if you’re looking to encourage a post, use the Boost link.
I’m using kbin.social on desktop and it shows up fine for me, not sure what’s going on on your instance