I can't see the rest of your instrument panel, but do you also see this on the speedometer dial?
View attachment 109080
If not, and lacking any current DTCs to go on, I'd suspect there is a problem with the DCA (Distance Control Assist) system, which apparently you have since you indicate you have ICC (Intelligent Cruise Control) and they are both part of the Technology Package option for your model year. DCA uses the same radar sensor in the front of the car as the ICC, FEB, and PFCW. If there is a malfunction of the DCA system, then you will see the warnings that you posted above.
You said a dealership replaced a computer. You might ask them if that was the ADAS control unit they replaced.
You also mentioned that this appears to be high temperature related. Another possibility is the ICC radar sensor temperature is too high and the fail-safe when that happens is ICC, DCA, FEB, and PFCW are cancelled. I suspect this is a temporary DTC that clears once the ICC temperature drops to an acceptable level. If you have an OBDII scan tool (which every car owner should), the next time the malfunction alert comes up on your information display, scan the car immediately BEFORE shutting off the engine. If DTC C1B85 is displayed on the scan tool, that indicates an abnormal ICC sensor temperature. Once the ICC sensor cools down, the DTC should clear itself.