For support or others to better help you can you provide further information.
What devices other than your MacBook are you syncing between, how many computers, what are there operating systems, what version and build of Moneydance are running on them, e.g. 2019.4(1892).
Are you syncing to any mobile devices.
What sync method have you set up on your computers, Dropbox Folder or Dropbox Connection.
It sounds like you have set up your primary computer to sync under FILE (MONEYDANCE on Mac) – SYNCING to create the /Users/jim/Dropbox/.moneydancesync folder but have you set up your secondary computer, your MacBook using FILE (MONEYDANCE on MAC) – NEW – OPEN SYNCED FILE?
If you provide more information it should be possible to provide more detailed help.