I noticed this a while back, but it wasn’t a show-stopping problem for me; now that I’m on a bug-report roll, however…
The iOS app seems to always display the original rate for a specific type of goal, even if the rate changes later. That “specific type” is goals where I’ve changed the due date and/or total and let Beeminder infer the new rate. This has been the case for several months at least (so predates anything that changed with the new design).
For example, I created my PPSTORMS goal with a specific due date and total number of words that had to be done by then. The initial goal date and total I entered came out to a rate of 1700 words/day (*). That rate has since changed several times (sometimes manually, by changing the due date or the total due; sometimes as the result of derailing). The current rate is 3471 words/day, but the iOS app has consistently shown me this since goal creation:
(The orange, blue, and green totals are correct; only the current rate is incorrect.)
In contrast, goals for which I directly update the rate itself do show the new rate in the iOS app.
(*) ETA: In fact, I probably rough-calculated 1700 words/day myself to create the goal, then immediately went in and changed the due date and total to their real values. So this initial rate was also direct entry rather than inferred.