This is different from it being offline, it's like the device is kicked off the associated account. A "something went wrong" window pops up with a "generate device code" button, with instructions on how to remove and re-pair the headset.

There is no way to even access wifi settings or anything else to disconnect the device from the internet. If it's still a problem much later in the day, I'll try turning off my router to see what that does.