I repeatedly notice that previously indexed folders in DEVONthink show different content compared to the folder contents in Finder. The files have NOT been modified or added in Finder! How can I get DEVONthink to rescan all folders and index any documents that are not yet present, so that DEVONthink and Finder are in sync again?
=> I have more files in finder than in DT!
Welcome @PG66
Try to search the forum or look in the manual 
Are the indexed folders inside cloud folders, e.g. iCloud Drive?
No - the folders are on my local Synology NAS
How do you mount the Synology in the Finder? And is the Synology updated only from this computer?
Hi Christian, the Synology is mounted via the Finder “Mit Server verbinden”. And the relevant directories and files are only updated from this desktop computer. If at all: All other devices are only reading from these directories. thx, Peter
Are you syncing the folders on the NAS with Synology Drive?
These folders are not synced!