I think what. you are seeing is just a very slow sync. Unfortunately Dropbox sync is very slow at this point. You could try connecting your device to power, and turning off the automatic sleep, and let it go for a few hours. See if the data appears.
The good news is that we just spent some time improving this a lot. We will release a new beta of the improvements today, and the the new version should be released in a couple of weeks.
Thanks Drew - I’ll try the beta, and give it a few hours. I also backed up the data folder myself, but would like to make sure I can rely on the dropbox backup!