The number of difficult words is inconsistent between the information that’s shown in my Pro page and the information that is shown on my dashboard. The following is what’s shown on my Pro page:
I see the same effect, plus the numbers of words on the web app and the android one also don’t match up.
One thing I notice is that in the pro page there are words listed which are NOT flagged as difficult words at all!
The course counter shows the correct amount of difficult words in the course, however when you view the difficult word list notice there are duplicates.
This is because the duplicate words are both pulled from the same row in the database. Your duplicated words would most likely be English to Chinese and Pinyin to Chinese, or something along that line.