I haven't looked at this issue in a long time, so I took a new look at what the Dropbox changes might have wrought. I don't think the changes are an improvement.
When you do a File>Save To Dropbox for Apps... from within RM for the first time, it creates a new folder in Dropbox called Apps\RootsMagic and stores your RM database there. That's where the RM App on your iPhone or iPad expects to find your RM database. Previous to the changes, you could see the Apps\RootsMagic folder within your Dropbox folder on your local hard disk. Indeed, I most typically would have updated my RM database for my iPhone simply by using Windows File Explorer on my Windows 10 machine to copy my RM database from it's existing location to the Apps\RootsMagic folder within the Dropbox folder on my local hard disk and then Dropbox would sync up as normal. The next time I used the RootsMagic app on my iPhone or iPad, I would get the newest version of my RM database.
With the Dropbox change, the Apps\RootsMagic folder no longer appears on my local hard disk. You can see it only by looking at your Dropbox files in the cloud. Your Dropbox app on your iPhone can obviously see the folder because that's where it finds your RM database for the RM app on the iPhone. Not being able to see the Apps\RootsMagic folder on your local Windows machine is a terrible design that serves no good purpose. I don't know why the change was made.
It is correct that File>Save To Dropbox for Apps... from within RM no longer overwrites the previous version of your RM database that your iPhone or iPad was using. Instead, new versions are added with version numbers such as (1) and (2) etc. You can see and choose these new versions from your iPhone or iPad. If you don't like the version numbers, you can go into your Dropbox account in the cloud where you can delete the old version of your RM database in Apps\RootsMagic and rename the new version not to have the version number. As I said before, this is a terrible design that serves no good purpose. There is nothing that RM users can do about it except to complain to Dropbox.
In case anybody is curious, I do have all the Windows 10 options for viewing hidden folders enabled. It's possible that the folder in question is still mirrored to my local hard disk and I just can't see it. But if so, I can't find the option to make it visible.