What you see when you scroll is not the updates from the sync, it is the generation of updated previews from the new settings. LR will only create the previews when it needs them (I.e. when they scroll into view).
If you want to manually generate new previews for all images after. Sync, select all the images, and choose "Library > Previews > Build Standard-Sized Previews" (or 1:1 if you prefer, it's slower).
Looking for advice. I took photos of a danceline competition. My folder structure is the main folder for the high school, with child folders for each performance. This structure remains when I pull into lightroom. Is there a fast way to copy those folder names to publish to smugmug. I'm trying to avoid recreating and naming folders. There are 70 for one competition. Thanks for any help.
You would get more help if you would start a NEW thread for a NEW question.