Hello!
My name is Gonzalo Varela, I am composer from Uruguay. Ever since I've been using the Track Manager I've been experiencing these bugs, regarding tracks that become hidden when they shouldn't. Since they haven't been fixed yet, I really hope this video helps.
https://www.youtube.com/watch?v=VTIh-frXUvQ
Sorry for the terrible video quality. I'll be here to clarify anything that needs clarification.