I am also running the latest preview build from https://infinitekind.com/preview
Updating did not affect my syncing between my windows 10 and windows 7 computers and my Android phone.
Perhaps check that syncing is still enabled under FILE – SYNCING.
If it is reset syncing as follows.
1. Under FILE – SYNCING set Don’t sync.
2. Do a FILE – EXPORT BACKUP.
3. Disconnect syncing on your two mobile devices. Any data not synced to your computer will be lost. Make a note of any un-synced transactions.
4. Delete the folder “.moneydancesync” in your Dropbox folder.
5. Under FILE -SYNCING set the same syncing method as you were using.
6. Start syncing on both your mobile devices in turn.