Air conditioning does not remember previous settings

https://drivers.lexus.com/t3Portal/document/om-s/OM50D48U/pdf/OM50D48U.pdf That's a link to the vehicle's owner's manual. Have a look. In briefly reviewing the information in section 5.3 about the climate control system, I do not see anything indicating that the system will retain the settings that were left on during the last use. That said, it's typical for the last settings to be in place when restarting the vehicle in my personal experience with most vehicles with automatic climate control systems. It could very well be a battery voltage problem, where there is not a sufficient amount of "reference voltage" when shutting off the vehicle to retain memory. Have your battery checked for ability to fully charge and also sustain a load to start with. Additionally, the climate control system may have an issue internally where it loses power for some reason. Check here too. www.repairpal.com/repair-shops Check that link for shops near you that can be of assistance also.