How to synchronize inboxes on my Mac and iPad

Dear Sirs,
I have a problem with synching the inboxes of my Mac and my iPad.
I currently have 1390 files in my “inbox” in my “global inbox” on my Mac

In the preferences I hav the following inbox checked for synchronization and I do not see any other inboxes to be able to sychronize.

On my iPad or iPhone however, I have only 103 files in the “inbox” in the “global inbox”
I have the inbox checked in the synchronization preferences on my iPad and there is no other inbox to choose.

And there are a lot of files missing on my iPad and iPhone accordingly. I could not figure out what is wrong. But clearly there is something wrong.

But what ?

I am using DT 3.7.2 on my Mac and DTTG 3.1.8 on my iPad and iPhone using the iCloud Sync Kit.

Thanks for your help

Which sync method do you use? Anything in the log messages on the desktop?

iCloud Sync Kit

That was the problem. There had been 2 files missing and 1 inconsistency.
Now the inbox is showing synchronization activities.