In the iPhone app, I left the app in the middle of a lesson and when I reopened it I noticed my progress was lost. The lesson opened several pages back from where I left off, and the known words and LingQs were lost.
This happened about a week ago also but then it fixed itself after a few mins of refreshing the page. I tried refreshing now and I still hasn’t corrected.
I realized what happened. Progress wasn’t lost, but for some reason the lesson opened several pages back and showed 1 blue word that I already added a definition for earlier, but all of the known words and lingQs after that word were exactly how they should have been. When I added the definition for that word again, everything was fine. So only 1 word was messed up.
Glad to hear you figured it out, thanks for letting us know!