I've noticed the same every morning that has been just below freezing. The camera heater used to run even with the car off, but now not only does it not heat while off/idle, but it fails to heat while the car climate control / front windshield defroster is on. Tonight was a good night for me to test before / after a firmware update (2019.32.12.2 to 2019.36.2.1) and both firmwares failed to activate the forward camera resistive heater. On both firmwares, not only was the heating element not activating in freezing temps (car reported interior temp of 27F), with the windshield defrost turned on, the duct heating was able to clear the rest of the windshield while the camera just sat there frosted (10+ minutes of defroster activity). Then after manually clearing the exterior frost from the camera, we end up with the interior still fogged, which blinds the cameras as the sun hits the fogged glass (see attached pics). The duct defroster/heater can't clear the interior fog from the camera area because the camera shroud blocks the air, so the only way to properly clear that space is with resistive heat.
The same actions were tested on my AP1 S. Camera glass began visibly clearing via resistive element within seconds of enabling climate/front defrost, and the camera glass cleared before the duct heater was able to clear the rest of the windshield.
I get the desire to save on battery, but in the case of my wife's morning commute, we are talking a 90 mile / 1.5 hour drive with all driver assistance / safety features disabled and constantly throwing warnings every time it is below freezing (and these are the times where safety systems are even more important due to slick roads / increased chance of accidents). That tiny bit of battery savings kinda backfires when the cameras remain blind even with the windshield defroster enabled.