https://youtu.be/ttZW-KehxxE
See for yourself. After moving like that a couple hundred times it eventually docks (by some miracle). Happened to 9 drones out of 10.
Changing the rail docker's orientation didn't work. I also tried to change the orientation of the pickup point, but that didn't make a difference either (does it even do anything?).
I can provide a bp of the drone if needed.