Hi!

DB stands for (D)rop(B)ox.

The sync wizard is... the Sync Wizard, in the Synchronization tab of Joplin's settings.

"Show Advanced" didn't have any options that provided a solution for me. The only one that seemed to apply was "Delete local data and re-download from sync target" and that didn't work because Joplin's id'ing the wrong sync target (the new "Joplin (1)" folder created on DB).