you for reaching out to the Community regarding your issue, although I am sorry
to hear that you are experiencing issues with syncing your attachments to the desktop. I'd like to see if we might be able to fix the issue you're having by recreating the dataset. To do this we'll want to create a new file as we're not able to delete our dataset from the original file.
You can make a new file by going across the top left to file > new quicken file. Once you've created the file you can exit out of the add accounts section when prompted. The article down below will give instructions on how to delete the dataset.
To switch back to your primary file go across the top left then you should see the number 2 (File name/Location) towards the bottom of the drop-down menu.
Once you've done this see if we're able to sync new transactions to include the attachments. Let us know how it goes!