Snyc not working after multiple reinstalls

I use Brave to sync four desktops and a laptop. For the last six months Brave sync has recurring issues. I have deleted the sync chain and started a new one twice. A key problem is bookmarks not syncing. As I sit here two folders of bookmarks are visible on a desktop in the other room, but not on the laptop I am typing this post on. I checked the desktop sync and the device shows up in the chain. I checked the laptop sync and the device shows up in the chain. What is the problem with Brave sync? This is a fundamental task that must work.