I am running Thunderbird 60.2.1 (64-bit) on my Macbook Pro. I am trying to use the offline and global search features. I have it set to sync all folders and all subfolders. However, when I synchronize (either with or without Go offline afterwards), it fails to download the messages in my inbox. It seems to download all other folders, and the subfolders of my inbox. But not the messages in the Inbox itself. This is most easily visible in what's available once I go offline.