a week ago
I updated my Q3 to v76 and my development productivity has taken a nosedive. In particular, it doesn't seem to be able to keep connected to adb consistently. Unity constantly tells me that "adb devices" doesn't list my device when trying to deploy, and if I do "adb devices" myself, I see the device appearing and disappearing constantly. On-device, I also sometimes get the dialog asking permission to enable the USB connection and when I confirm, it just pops up again immediately. No matter how many times I confirm (and even if I hit the "always trust this PC" option, which by the way is almost impossible to click because the button is off the bottom of the dialog), it still keeps asking.
This update also broke casting on my 3s. I keep getting a dialog that says "Casting has stopped" on the device.
8 hours ago
For me the problem was that the the "developer mode", though enabled in the Quest itself, was disabled in the Meta Horizons phone app. Enabling it caused the device to enumerate in "adb devices" again. But it also somehow disabled itself again while I was working. Very odd behavior. This update seems to be very buggy, I would even suggest it should be rolled back. I have seen random crashes and my app won't even run.