My story is very similar to yours. The differences are that my problem started in the second week of February and I live in Delaware. A local dealer had the car for most of a week and within two days after I got it back the problem reoccurred. I know that the problem is temperature related. My car is always outside. If the air temperature is 50+ the problem may not occur. Below that it will not switch to EV mode except when it is stopped. I know there is a small battery that is necessary for the proper operation of the computer that controls the EV/battery charge function. I'll let you know what I learn.
