I’ve got Brave on 2 PCs (Windows 10 Pro x64 on a LAN) with Sync setup.
When I move a subfolder of my Bookmarks from within a subfolder to the Bookmarks bar, far left by dragging and dropping the folder, it appears briefly (about 1 minute) in place and then it disappears and seems to be back where it was.
I can make it stop this behaviour by switching off the sync bookmark feature in the PC. But that’s not the point surely.
Using Brave [Version 1.3.67 Chromium: 79.0.3945.79 (Official Build) dev (64-bit)]
on all 2 PC devices.