That sucks - I hope that you can find a solution to this mystery but you would think it's not rocket science and TPMS should be easy to reprogram or something. I have to ask though, did you check if the tech drank his beer already? You could retrieve it.... J/K

 

There's a happy ending to the story — a local Lexus/Toyota specialist identified a sensor that needed to be changed. I don't know whether it was damaged during the tire change at Costco or battery was dying, but a new Denso unit fixed the issue.

 

Thanks for the update - So many people come here for help and then never come back and give us closure so much appreciated, and happy you got a good outcome

 

Thanks for reporting back.

I would still bet money it was the battery.
The sensors only job is to transmit information to the vehicle...when it stops doing that, then it's no longer of any use.
The simplest explanation of why it would stop doing that is the battery dying.
Consider that all the sensors were put in the vehicle at the same time, so if the battery was low on this one, it wouldn't be unreasonable that the remainder will be getting low as well.
Realistically one sensor is going to be low first, and another last, with the other two in between somewhere. Just something to consider if the issue returns in the next 3-12 months.