I have the exact same issue on my 2013. Have you had any luck with this?
Yes. It was the thermostat all along. I have the front and rear temperature sensors replaced ($1300). When that didn’t fix the problem the only thing left was to replace the thermostat which of course necessitated replacing the water pump and the serpentine belt. Fortunately, I have enough chops to be able to have done this myself and saved at least $2000. Not only did this solve this immediate problem, but for the first time since I owned the car, the start/stop feature worked, which indicates to me that the thermostat was never good. I too thought the temperatures were normal, but what I didn’t realize is that normal operating temperature is 200°F. It was never that.I have the exact same issue on my 2013. Have you had any luck with this?