BTW, BlackBerry Hub used to sync everything perfectly, but after i upgraded an old SOGo to a newer nightly build, it stopped working (and doesn't work with the latest nightly build either.) No sogo config file change at all, and "Personal Address Book" has option "Synchronize (Microsoft Enterprise ActiveSync)" enabled (it cannot be disabled actually). So i think it might be a SOGo issue and i appreciate if you can try to reproduce it.

• Just grab an Android phone with OS 6 or 7, install app "BlackBerry Hub" from Google Play Store. I tried with BlackBerry DTEK50 and KEYone. but BlackBerry Hub is available on all OS 6/7 devices, not just BlackBerry devices.
• Setup an ActiveSync mail account with BlackBerry Hub, choose to sync Contacts.

It is the same using the default Exchange connector on Android OS as well, contacts (except sometimes a few) don't get synced. I sometimes get one to sync by saving a change to the contact in the web-interface, but this doesn't work reliably.

@zhb It works for me. I tested with BlackBerry Hub on a device with Android 6.0.

Unfortunately, it doesn't work for me with Android 6 + BlackBerry Hub. Any debug hint for me?

hmm.
.) check the eas cache to see whether there are entries in the contact folder
sogo-tool -v manage-eas listfolders <user-id> <device-id>
.) you could provide me a sogo.log with SOGoEASDebugEnabled = YES when you create an eas profile for a test account and I'll have a look.

Following sed (or a similar one) would strip sensitive data:
sed -e '/<ApplicationData/,/<\/ApplicationData>/{H;$!d;}' < sogo.log > sogo-stripped.log

I can see data in the output of "sogo-tool -v manage-eas listfolders <my-email> <device-id>":

#########
Folder Key: R6QS4L64CD2FD4AJF5EQKLEUH0+vcard/personal
Folder Name: Personal Address Book

metadata Name: {CleanoutDate = "2017-06-05 01:18:45 +0000"; DateCache = {}; FolderOptions = {BodyPreferenceType = 1; FilterType = 0; MIMESupport = 0; MIMETruncation = 8; }; SyncCache = {"1E5D-592E7580-101-7824CD80.vcf" = 1496216910; "1E5D-592E7580-103-7824CD80.vcf" = 1496216910;
...
"1E67-5934B180-1B-69E4000.vcf" = 1496625516;
}; SyncKey = 1496625545; UidCache = {}; displayName = "Personal Address Book"; }
###########

Even worse, it didn't sync the default "Personal Address Book", but it synced another one even i didn't have option "Synchronize (Microsoft Enterprise ActiveSync)" enabled for the address book. And now it doesn't sync any folder. No changes made to both server side and client (phone) side.

I will capture a sogo.log with "SOGoEASDebugEnabled = YES" option enabled soon.

Thanks for helping.

Odd enough, it now syncs "Personal Address Book". No changes made to both server side and client (phone) side.

Re-open if you have hard evidences.