I've heard of this issue, but have not experienced it personally with my 2017 FFE. I'm in Houston, where the summers are generally very hot and humid. My wife did say she saw it happen once, but it did not last very long. My car is generally in the garage when at home, because that is where it charges. I think the issue may that on newer models, part of the HV pack is in the cabin, so when the interior gets very hot, the battery is heating up as well. I have a couple of suggestions that may help.
(1) we have the darkest allowable tint on the rear windows. This really helps keep the infrared light out of the interior. (2) Use a reflective window shade on the front window. (3) Crack the windows and let hot air out. This will help equalize the interior and exterior temps, instead of creating an oven inside the car. (4) The car can be precooled before departure. I suggest remoting starting the car, or using the preset departure start to give the car an opportunity to cool down before entering. (5) if the full vehicle range will not be utilized that day, the car can be idled with AC running for a long time without suffering a substantial range hit. Once the interior has been cooled, it takes less energy maintain that lower temperature. So if you're out shopping or running errands, you can leave the vehicle running and just lock the doors.
I hope this helps!