Symptom: Nothing happens when you say Hey Grok.
Fix: Turn on voice activation in Controls > Audio > Grok Settings (Tesla's support page; the same settings are also under Grok > Settings). Confirm Premium Connectivity or Wi-Fi, and try an American English pronunciation: the 2026.20 release notes said the wake word is trained on American English (later notes we checked do not repeat this). Press and hold the steering wheel mic button to open Grok without the wake word.
Confidence: medium
Sources: [1] [2] [3] [4] [5] [6]
Related: Why isn't "Hey Grok" working in my Tesla? · Grok Activation & session commands