To follow up and close this out: Lucid service checked the error logs and data from my vehicle, both remotely and later onsite for a mobile service appointment, and could not find anything to flag as the culprit. The issue has not appeared again. The vehicle was under software version 3.6.0 when...
My Gravity Touring threw up a “pull over safely” warning while driving 50mph. It happened immediately after changing from standard braking regen to high.
No propulsion, the vehicle would only maintain current speed (but if the speed went down it would only coast at that speed or less, so on...