Yes, you are making progress. That's great.
The explanation about setting Bar 1 only addresses the count-in and location of the audio wave file within the Audio Edit Window. You only need to do this if you are listening to the audio file before running the ACW or Stem Splitter. Stem Splitter is a separate function from that.

The Audio Chord Wizard and Audio Edit Window are both single track editors. Setting Bar 1 of audio on the Audio Track is done prior to using the Stem Splitter if you want to set bar 1. If you open an audio file from within the Stem Splitter, make all your settings and solo the Master File audio track in the BIAB Mixer. Creating the tempo map will also sync the other stems once the creating the tempo map and running the ACW is complete.

Using the Stem Splitter, the Style should be disabled and I always solo the Master File located on the Audio Track so that is the only track sounding out.

There have been issues in the past using styles with RealTracks that disabling the style doesn't mute the RealTracks. Solo the Master File track and that will solve the issue of hearing other tracks while you are creating the tempo map. Once completed, the tempo map will be synced with the other stems.

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.