Thanks for the bug report and sorry for the trouble! We’ll check it out. To be clear - did you add the sentences to your favorites via sentence search on the web? Then you noticed the jump in your Fast Track sentences played count prior to playing your favorites offline?
We’re still working on getting downloadable Fast Track support added for more language pairings. It looks like you’re playing learning Swedish from German so I processed the Fast Track for that pairing to be downloadable. Please let me know if there are any other language pairings you’d like to see downloadable and we can work on it.
We’re also working towards more offline playable content for the mobile app. The new custom cloze-collection feature will be downloadable, and ideally you’ll be able to play Grammar Challenges and all the play modes offline as well, but we’ll see how that works out.
Anything else please be sure to let us know. Thanks again!