Not really addressing your specific problem, however for future reference or if you can find a friend with a P3 you can use to D/C:
Lipos like a storage state of 3.80 - 3.85 V per cell.
Usually that ends up being 44%-50% on these Phantom 3 batteries. I use the setting to display the cell voltage in the GO app to make sure that I'm where I want to be when I get home. (I usually land with about this amount of charge remaining anyway.) That being said, I used to do the 2 solid lights with the 3rd blinking rule, but after I found that actually wasn't representing the proper storage voltage I now take a reading from each of my batteries in the quad after flight (a few minutes after landing to take as much load off the battery as possible) or plug into quad after charging to what I think is storage to double check the voltage. It's a little time consuming, but it's worth keeping those pricey batteries in peak condition.
This is why the automatic D/C feature is helpful, but not a perfect solution. It will D/C to about 65% and as I stated above, that isn't anywhere close to storage voltage although significantly better than remaining fully charged for long time periods.
I rely on principles of battery chemistry rather than DJI instruction to guide my ideal battery care.
Also, if I know I'm going to fly again within 48 hrs, I'll allow myself to go down to about 20% - 25% on a flight. Otherwise I try to land at 45% so I don't have to bother with recharging up to storage voltage.