Hi, I am a new-old user, started with Cakewalk back in the 90s then moved on to other DAWs and have come back a few weeks ago due to an emergency studio I had to set up while in quarantine, so I am really thankful to Bandlab for this opportunity to keep making music in these sad times: here is a little contribution to hopefully help troubleshooting and fixing this extremely frustrating bug
I have experienced this issue a few times already, and I am not sure about the previous times, but this last time it was definitely following an update in the MIDI Devices: I reconnected my USB keyboard controller and restarted Cakewalk to make Cakewalk "see it" (this is also strange: sometimes Cakewalk sees that something has been connected or disconnected, other times it doesn't). When I opened the project after this, the mapping between the 3 active instances of Xpand!2 and the associated instrument tracks was all mixed up.
I was able to restore 2 of them through the MIDI section of the Inspector, but the third one was frozen with the freeze icon grayed out and there was no way to unfreeze it other than delete it and insert a new one. All of this, including trying to understand which Xpand!2 instance had ended up on which instrument track, looking for solutions online, etc. took me more than one hour for just 3 tracks, so I can see why other users are so frustrated as well.
Coming from other DAWs, I have to add that this wouldn't be such a bad issue (apart from the misteriously frozen and non-unfreezable track) if there was a more user-friendly way to check and change the mapping between instrument tracks and "synths" (by the way, why "synths" and not "VSTi"? most of my VSTi are not synths but samplers...)
My regular workflow (and not just mine, of course) is to create (or have in my template) an instrument track for a certain instrument, e.g. piano, and then experiment with different VSTis until I find the sound I have in my mind, and this simple task is made terribly cumbersome by the way the functionality has been implemented: as far as I understood reading the manual and online resources, I am forced to pick an instrument when I create an instrument track (which shouldn't really be the case, especially working with project templates), and once it is created, the only way I can see which VSTi (including instance in case of multiple instances) is associated to the track is to open the inspector and navigate to the MIDI section: why can't I just have a field in the main track view showing that information and allowing me to change it? This is the case for pure MIDI tracks where I have this in the Output field, but since instrument tracks output refer (correctly) to the audio output of the track, on those tracks this information is lost, which is where it would be most essential to have it (who works with pure MIDI tracks anymore? yes, I can see who, but that's definitely not the majority of users)
Similarly, why on earth when I delete a "synth" from the rack view and uncheck the "delete associated tracks" option, does Cakewalk automatically split my instrument track into a MIDI track and separate audio track? If I originally created an instrument track it's because I'd rather use that than a MIDI-audio pair, so why that forced change? This forces me to create a new instrument track, copy-paste the MIDI data and delete the two unwanted tracks while I could have simply used the existing instrument track and associate a different VSTi to it.
For future evolutions, I strongly recommend to check how the instrument track functionality is implemented in the most popular DAWs: this does not mean they are perfect, but I certainly find them more user friendly in this respect
Thanks!!