With the amount of authors currently on this site, it's not wonder that you may struggle to find any of your Hubs in any of the lists. Your best bet is to write the best content that you possibly can, and then do some SEO and back-linking to other sites. Especially, if your main purpose of being on HubPages is to make money or get exposure to your content.
Also you mention that an article that was published twenty minutes ago is hard to find, so why not do an experiment? Publish a Hub then straight away check the category which fits the Hub, in the "Latest Hubs" section. If you can't find it even after one minute has passed, it's possible there may be an issue with the website... Make sure to post your results back here!