DTTG Partially out of sync

On Mac DT3b4 I have 3 databases, one named “Home”, which has 44 top level groups and no files in the top level.
On iPad DTTG Home has 7 extra top level groups and 100’s of extra files of various types: image, pdf, Word etc.
On iPhone DTTG Home matches Mac Home. Files are Downloaded on iPad, On Demand on iPhone.
Thorough verification of Home database on Mac Sync Preferences was successful.
I do not know when this sync discrepancy occurred; I use iCloud sync.
Searching for the extra iPad groups on the Mac finds them all as sub-groups of the top level group “Articles (Dropbox)”, an indexed folder on Dropbox, mostly sub groups of groups which are themselves sub-groups of groups or sub-groups. Too many extra files to check all, but looks like they are from same indexed group.
Noticing that some Mac sub-groups seemed to have disappeared on iPad I searched on iPad for a file from the missing group: Home/Articles(Dropbox)/PC/Hardware/Apple/. (the sub-group Home/Articles(Dropbox)/PC/Hardware/ and its 6 sub-groups are also missing) DTTG found the file - a pdf. Looking at the “Move” dialog showed that the file was in the ////Apple group, but the Apple group was greyed out. Having looked at the pdf, on the next automatic sync the Apple group on the Mac moved from Home/Articles(Dropbox)/PC/Hardware/ to Home/. On Dropbox the file and the Apple folder are still in the Home/Articles(Dropbox)/PC/Hardware/ folder. The Mac DT3 Log showed File/Action: Home > Apple, Info: Couldn’t move item. On iPhone the Apple group is now missing from Home/Articles(Dropbox)/PC/Hardware/. The new Home/Apple/ group only exists on the Mac, not on iPhone or iPad.

How do I correct all of this? How do I avoid this happening again?

Sounds a little like what I’m experiencing DTTG not syncing correctly from Mac (Inbox / deleting items)

This is not the best place for this kind of issue. In DEVONthink To Go 2, select Help > Contact Us to start a Support Ticket. Thanks!