I got a call from the Miami Service Center today in response to my call last week about problems since the 2.2.2 update. They had not heard of anyone else having 12-volt power interruptions.
However, they currently have two cars in the shop relating to problems with Alexa since the update. They either find it takes a while after starting the car before Alexa will respond, or Alexa will not respond at all until the car is rebooted (the issue I am having). They said the Lucid software team is already working on a fix which will probably come out in an update.
They said they would send a mobile tech to check out our car, but since it sounds more like a software issue than an issue with the car itself, I declined until I accumulate further experience with the issues relating to 12-volt power interruption and Alexa.