Do you happen to have "Joe Mode" on to reduce the volume of chimes? I've got it on, and occasionally I'll disengage and just barely hear the chime over the radio.
I don't use Joe Mode and I do hear the chime, but of course that alerts me that FSD is not engaged after it has already disengaged.
Here's an example of when I believe it's disengaging with no prior warning, though I guess this would be AP, and not FSD. I'm driving down the highway and see that it narrows down to one lane because of road work. I wonder to myself how the car is going to handle the situation. As it approaches the narrowing point, I see, and I believe the car now realizes, that it has gotten itself into an untenable situation and it just disengages, with no prior warning, and the car is now in my control. Granted, I've got my hands on the wheel so maybe it's primed in this type of situation to respond to virtually any amount of input with a disengagement. If true, then this is practically tantamount to my original point, as I would not expect the car to disengage with such little torque.
For some reason this also seems to happen sometimes when it's making a protected left turn and on the outside lane of a two lane turn. It's either disengaging on its own or the torque needed is very minimal, which then begs the question as to why torque requirements to disengage would vary so widely.
My theory is it's
1) disengaging with no input and with no prior warning, or
2) disengaging with much lower torque requirements than normal because
3) it finds itself in a situation that it does not feel comfortable handling.
It would be hard to convince me this aspect of FSD is not dangerous. Overall I do not believe FSD is dangerous, and I use it routinely with my family in the car, etc.. I also have about 90% of my net worth tied up in Tesla, so I definitely have no ulterior motive here. Just passing along my observations and opinions.
Remember when we used to debate about the fonts and typefaces available on computers? How pricey they were, how the Macintosh system had this typeface available for use, while Windows had this typeface available? About how typeface packages cost so much, etc? Now of course we look back at that rather sheepishly and wonder what all the fuss was about as now typefaces are essentially free and ubiquitous.
I imagine all this hand-wringing about FSD will age just as well.