> FSD reliably and repeatedly tries to stop at green lights on a 50 mph road near me
I believe that's a "feature". I had it on a loaner too and it wants you to give it permission to cross the intersection by pressing down on the drive stalk or briefly press the accelerator pedal.
https://www.tesla.com/ownersmanual/modely/en_eu/GUID-A701F7D...