@russ thanks, I removed the deviceType from my json file and had Alexa rediscover and they do still dim. I edited my previous post.
It should be noted that using dim turns the device to that value. So if you turn a light on (100%) then say dim 20% it doesn't set the light level to 80 but instead sets the light level to 20.
At least that's the way it works for HG.