I had no problems upgrading my phone and adding devices (another phone and two tablets) with the sync key. Two phones synced fine, two samsung tablets synced to 50 % and stuck there. Cannot complete the sync on those devices. Syncing from dropbox for all of them. Android tablets running android 7.0. Two phones are both pixel 3 running latest android (10)
Update: another person said it took 5 minutes to sync the first time. I let mine run and after 6 or 7 minutes and it finished. Syncs after that were quick.
Hi @J_Borak
Thank you for the update. The initial upgrade sync may take some additional time, however as you note, subsequent sync’s should be fast. Thanks!
Yep. It took more than 6 minutes initially on each of the tablets (Samsung), the Pixel 3 phones were really quick.
Maybe the tablets just do not have enough horsepower. Not sure but all is well that syncs well 
Love this product! Thanks
I came here to report this same issue. My Android phone sync’d in just a few seconds, while my Samsung tablet gets stuck at 50% even if I leave it for a few minutes.
I was wondering if the sync was just taking a while, but it’s unclear just how long I should wait, and maybe the app should give more feedback instead of just getting stuck at 50% forever.
I’ve tried waiting longer, but the tablet eventually goes to sleep while waiting for sync to complete, and upon wakeup, the app has closed itself and the sync.lock file needs to be deleted to restart the sync process again.
I’m trying again where I tap the screen every minute or so to try to prevent the tablet from sleeping, but this seems crazy. It’s not a good upgrade experience.
After keeping the tablet awake during the sync for over 10 minutes, it still failed to proceed past 50%. I finally aborted the Sync by pressing the Back button.
Previously when I would abort the sync this way, the progress bar would freeze, and the entire app would also freeze. After a minute, Android would ask me if I want to force close the app, which I did. I’d be able to relaunch the app, and an Integrity check of my database either showed small index errors or no errors.
However, this time pressing the Back button just brought me back to the app as if nothing was wrong. The Last Sync data was still shown as Nov 11, so I knew the sync didn’t work. I decided to try it one more time, and the sync proceeded in just a few seconds, then completed.
I don’t know why waiting a long time didn’t work, or why the sync never completed, or why it now completes. All in all, a frustrating experience.
Here’s some version info about my device, in case this is useful to you:
Samsung Galaxy Tab, SM-T713
Android 7.0
Kernel 3.10.84-14953299
SE for Android: Enforcing SEPF_SECMOBILE_7.0_0010
ASKS v1.4.5 Release 180122
SMR Jul-2019 Release 1
@ZipFoxtaur - we believe the issue for slow sync on certain Android devices has been fixed in a recent update. Could you download the latest version of Codebook for Android and see if this is resolves the issue you were seeing?
I haven’t noticed the issue since the latest update.