(Please see post #7 for detailed step-by-step.)
Sometimes when I have a project, let’s call it “project A”, open and I open another project (project B) and activate it, then close it to go back to project A, some automation tracks will have their “read automation” turned off when they were previously on.
Note that it’s not the whole audio or instrument track read automation which is turned off, it’s just some of the automations, i.e. the volume or cutoff automation. It is stealthy for this reason, because the green “R” for the whole track is still active, so you need to expand the automations to see that they have been turned off. It is repeatable; see attached images.
What makes this more peculiar is that it’s not just a visual glitch; certain automations are actually turned off even though it shouldn’t be possible by clicking individual automations’ “R” button; only the mute automation button should be able to do this.
It is an issue and I’ve gradually learned that if a track sounds significantly different after a while, this may have occurred.