I was reading somewhere here on the forums, that DJI would provide support for your M4P drone, but you will have to pay for all repair services as they would not grant warranty for a drone purchased in other region (Korea, Japan) and as you know...
Just to add to this - It's not always like that! This really depends on GPS signal strength your RC can lock on. I had situations when RTH with DHP drone was few feet away. Nothing too crazy, but way more than 1.5 feet, I seen situations about...
I have been vigorously testing RTH with DHP feature myself. I don't have the RC 2 Pro (only the RC2) and according to my tests, drone behaves pretty much how Aeolus described above. When RTH is activated drone comes home, when DHP is reached it...
An update to my case, in case it might be helpful to anyone.
After contacting dji support, they suggested to send the unit back to them for inspection.
Before doing so, I thought to try one more time to self-calibrate the sensors.
DJI support...