@Rox1, this will likely turn out to be some configuration issue. My guess is that iOS is fine and the problem is on the PC side, as that’s where you’ve changed things. On the PC, triple-check that your Scriv 3 project folders are located in the same Dropbox folder where your Scriv 1 projects were located, because that’s the Dropbox folder to which iOS Scriv is pointing.
If that’s not the issue, have a look at L&L’s iOS Sync troubleshooting guide.
Also, see this thread from a poster with a similar challenge.
Best,
Jim