Couple things here the Aeros does not send song messages, or any messages currently. It only sends out what it receives from the MIDI in, it does not currently generate any MIDI messages itself.
The BB has the capability of changing songs with a midi command, the Aeros does not have this capability, it does not currently react to MIDI song select messages like the BB does.
We understand that this is not optimal, and we are working on solutions, but there is not something we can do immediately. If you would like, there is already a committed forum post on this topic, if there is anything that you do not see add it there, you are free to add any comments or suggestions.
I want to make sure, is the BB you’re using on version 3.8.0?, And is your Aeros on version 3.1.18?
If so make sure that the MIDI Out port of the MIDI sync breakout cable is connected to the MIDI in port on the Aeros. Also, confirm that the BB is sending out messages on the same MIDI channel that the Aeros is listening to. Setting both to default will fix this.
When you are on a blank song, do you see the Aeros say MIDI sync is on? If so that means that the connection is working, if MIDI sync is not on, that means that there is a problem with the connection.
To be clear the Aeros cannot act as master, the BB or another MIDI clock device must act as the master. This is something we hope to change add to the capabilities of the ALS soon, but we are not there yet. Also, the Aeros cannot change tempo once a song has been recorded to, the song must stay at the tempo it was recorded and a nasty bug will occur if the Aeros internal tempo is mismatched from BB. In this case, the tempo will not change along with BB.
This is not a bug, but a feature that is not yet present on Aeros firmware. That being said, we have all the intention of including it as soon as possible.
For this reason, I will tag this as #not-a-bug.
Please let me know if I missed anything or can clarify something!