I retried and now it has selected everything to sync even though I know that most of the files haven't changed.
Background: I transferred everything from my old desktop computer to the NAS. From that, I selected a number of folders I knew I would need access to, to OneDrive.
Since moving house, I have a new laptop and want to move my usual files back to my computer and use my NAS as a backup. I obviously, only want to move files that are new/changed (there are probably thousands that haven't when I include my Documents etc).
To break the task down, I thought I'd compare/move files in chunks, starting with my programs folder.
I have already been through the NAS drive and deleted all the ones I have already installed - these have all been prefixed with x - in the folder on my laptop.
What I expect to be copied are new programs I've downloaded but not installed plus all the installed programs. The rest should be ignored (the majority).
I have noticed that the date attribute has changed to the date the files were synced to the laptop, so I chose to compare the size. I can't think of anything else about the files that should be different for DOpus to think they all need copying.
Please show us how the Sync panel is set up (in case more than just the Compare drop-down has changed), and a couple of examples of things that it wants to sync but you don't think it should (so we can see if there's a difference between attributes that explains it).
Also note that if you rename a file or folder on one machine but not the other, then those are going to look like two different files/folders to the sync tool, and it would want to copy them over unless you renamed both sides to be consistent again.
If you're renaming one side but not the other, and just want a list of all folders which are (or aren't) on one side vs the other (based on their names), then there are ways to do that, and it might be more suited to what you're aiming for.
1 - This is the set up before anything clicked.
2 - Result after Compare clicked
3 - Result if I click Compare for just the folder called 6D (see 4) yet this folder was included in the original list of folders due to be synchronized.
There is obviously something about the folders in OneDrive that makes them different to the original ones on the NAS (drive F).
Regarding your last point, I'd be interested to know how to get a list of all folders that exist/don't exist on one side v the other.