This app was mentioned in 1 comment, with an average of 2.00 upvotes
This? If so, that makes things much more difficult to debug, since mobile browsers don't tend to have the same set of developer tools as desktop browsers.
I'd also in general recommend using the mobile website (feedback to /r/mobileweb) or one of the many native apps (I most like Relay for Reddit), but I don't remember which of those support subreddit creation.
Can you try using mobile Chrome or mobile Firefox? We don't target mobile browsers for the desktop site, so your chances of things working well are much better when using a common rendering engine. It also gives us a good point to start looking for issues.
Edit: Also, are there any error messages at the top of the page? I've seen issues with the auto-scroll to the error, and on a small screen it's unlikely to be in view.