I had a task in one list that I noticed was the first item on my iPhone but missing on the web version (they are both sorted the same way). I had figured out to click the refresh icon or to close and relaunch the app - and these steps didn't result in that item showing up in the web version (I was also reloading the entire page to be thorough.) I tried (a) renaming the task by appending some words, then syncing (both with the refresh button, and by closing/opening the app) and reloaded the web view - task not listed - and searching for it wouldn't show it, (b) moving it to a different list, rinse, repeat - no effect, (c) changing tags, other things - no effect. I have hundreds of tasks. I'm not going to go through every single item on both sides - especially when I can't fix the problem anyway. I reset the app and it lost that task for sure. I hope whatever issues you folks have with syncing, you fix it. If this happens to me again, I am done trying with it. I would suggest you focus on correctness first and everything else afterwards.