Is this just me? Am I missing a setting?
No.
Release date is not working either. More casualties of the IMDb redesign, it seems.
BTW, in case anyone is interested (i.e., largely off-topic)...
AFAIK, there's no "category" at IMDb, and
Category has never been filled by the IMDb plugin. I'm not sure of it's intended purpose—it may be used by other plugins. I fill it with Allmovie "themes."
Release is not used by plugins, but it's handy for other things because it supports sorting and grouping like other standard fields, and can be used in the list title format. I use it for "movie series."
The IMDb plugin will download
Box office, but the data isn't very useful because it's not consistently aggregated. The plugin can only get one number from a list of "gross" figures. That's never worldwide gross, although that's sometimes in the list. It's sometimes domestic (USA) gross, but is often just the last weekly figure (which might be the same thing). If this information is important, I recommend getting it manually using a
Box Office Mojo (the source of the IMDb data)
Web search...
http://www.boxofficemojo.com/search/?page=releases&p=.htm&q=%s%u