We've been noticing a lot of unusual activity with the Apple Podcasts directory lately. It's possible Apple is working on the directory and that's causing problems like yours. I looked at the source code of your podcast RSS feed, and the first iTunes category tag is set to Business, as opposed to careers. But the show is still being listed under the Careers category. Best thing I can suggest at this point would be to contact Apple Podcasts support. Use the "Contact Us" link at the bottom of this page:http://itunespartner.apple.com/en/podcasts/overview
Let them know you've changed your category your podcast feed but it hasn't updated in their directory. Sometimes, they have to manually fix these things on their end.