The "b" key goes to the first beat that the analysis algorithm detects.
This machine sometimes works better and sometimes worse depending on the track and the beat.
You should use the Cue point as the starting point.
To set the starting point use the "q" key this key stops the track, but not only. When the track is playing the "q" key will stop the track and go to the starting point. When the track is stopped and at the starting point the "q" key will play it as long as it is held. When the track is not playing and not at the starting point the "q" key will set the starting point there.
If you don't like the starting point pause somewhere else and then press "q"
To rewind the track use F10 or Ctrl+Alt+Up/Down arrows to select a unit and then ctrl or Alt and Left/Right arrows
PS instead of using Ctrl+Alt+b and then Ctrl+p or Alt+p you can use Ctrl+Shift+p or Alt+Shift+p these shortcuts play and try to automatically sync the tracks.
All the best Zenek