[TLockhart]

The activity key seems to work for me (but not 100% of the time, which is perplexing).
However, as far as I can tell the only door which unlocks is the driver's door. Not the tailgate, which one might think would be the most useful, since I'm standing right in front of it to unlock the car! I tried stashing the fob inside the tailgate as well as inside the driver's door but did not find a difference in behavior.
Do other people see this limitation, or know of settings which can be adjusted to get the tailgate to unlock when the activity key unlocks the car?

 

[MKenM]

There are two ways here is # 1

To unlock the vehicle and disarm the alarm system, press the smart key's unlock button. The vehicle unlocks in one of two ways:

Single-point entry: Unlocks the driver's door only. A second press is required to unlock the remaining doors and the tailgate.

Multi-point entry: Unlocks all of the doors and the tailgate on the first press.

To change from single- to multi-point entry, or vice versa, press the smart key's lock and unlock buttons simultaneously for 3 seconds. The hazard warning lights flash twice to confirm the change.

# 2

Using the steering wheel controls press OK and ten scroll though until you see a menu item about locking and unlocking the vehicle. Just follow the prompts.

 

[Roverdude]

That's odd. My activity key will unlock all the doors and tailgate. I don't recall there being any settings or anything that lets you chose whether your activity key will unlock a single door or all of them. Might be worth checking with your dealer.

 

[TLockhart]

Multi-point entry: Unlocks all of the doors and the tailgate on the first press.

Yeah that did the trick!
One might wonder why the tailgate doesn't unlock with the activity key no matter what, but I think the multi-point entry is a more useful mode in general so will stick with that.
Thanks!