AXS Rival Rear Derailleur Not Shifting - Mechanical Issue?

Brand new Lauf Uthald with AXS Rival Max 36T 2x. Pressing the AXS button on the rear derailleur I hear the stepper motor and see some movement, but not enough to shift the chain.

I also see this plastic arm mounted moving. Is this a faulty part / poor install?

Brand new Lauf Uthald with AXS Rival Max 36T 2x. Pressing the AXS button on the rear derailleur I hear the stepper motor and see some movement, but not enough to shift the chain.

I also see this plastic arm mounted moving. Is this a faulty part / poor install?