My site was fast indexed in Google. But almost 1/2 hour after I had made a new post (with wordpress as CMS), my traffic suddenly dropped until there was no traffic and no keyword rank although the site still increases in indexing on google.
Google's index is always changing, especially if your site is new it will always move position. You need to wait at least 1 or 2 months for it to stabilise a bit but even then it will still be moving
Certainly not because of the content, since you have a dynamic website. My personal opinion is that, the categories should be more prominent. Also, they could be organized better, in terms of titles and positions.
Dont worry. New sites usually rank temporarily then Google swallows them for a bit and spits them out at their 'real ranking' Give it a few months, and read up on the sandbox