From the moment I got my Fire, there has always been something weird about the port. I either have a hard time getting the thing to stick, or the Kindle gets corrupted zips flashed to it. I personally think it's the Kindle itself and nothing to do with the charger. I don't care about the corrupted files because it can always be the K3 wire I'm using, but I'm worried about the wiggling.
And no, I don't have any other chargers except the K3 one. I told myself I wasn't going to try and get similar chargers to work with same voltage devices after almost electrocuting myself a few years ago.