On current software version 2018.50.6.
I have been trying for the past hour now to wake up my car over 1,000 miles away to check on it. I hoped Tesla had fixed this issue by now, as I never experienced this before parking at my house and waking it up to warm every morning. It is also charging when I connect to the car at home, so that must be keeping it awake.
It is inconvenient since my car is plugged in, was charging, and completed in the middle of the night last night. I wanted to raise the charge limit before I got back but it looks like I will be unable to if it persists. The car should never go into a deep sleep knowing the charging cable is plugged in. It may have crashed like I see it do frequently.
The odd thing is that I've had it work flawlessly and wake up the car after sitting overnight not plugged in. My gut feeling is that this is just is just flat out a bug issue that has yet to be fixed.
I will update if the car wakes up eventually and let you all know. What may be happening is once the car is not in a charging state it goes into deep sleep to preserve battery life. I assume that the car will wake every couple hours or so to see if there were any pending pings to it, then it might stay awake for the next 15-30 minutes.
After trying all day to connect to my car, I finally was able to wake it up today at 3:15PM. I had been trying all day periodically and at times consecutively 4-5 times until timeout.
I tried waking my car up starting this morning at 8:00AM. It finally woke up for me when querying the car at 3:15PM. My above hypothesis that the car goes into a "deep sleep" seems correct. The car became unresponsive for 7 hours.