With the latest release of Lightroom CC (also called version 6), it seems that Adobe has reduced the Identity Plate size. Just last month I wrote about getting the identity plate back to displaying correctly when you were using Lightroom Mobile. As soon as I upgraded from Lightroom 5 to Lightroom CC I noticed that my customised Identity plate was cut off.
At this stage it doesn’t seem like there is any official post from Adobe about what the new size should be. At least I didn’t find any so far. So after some trial and error I noticed that using a Height of 40 pixels (40 px) seems to do the trick. However your logo and identity are much smaller in the scheme of things. My previous identity plate was 60 pixels high.