Docking ports break by unknown forces in orbit

It occurs when docking with a non-player craft in orbit.As soon as the crafts are indicated to be fully docked, the connection breaks between the docking ports.

To reproduce(in the sandbox below):
1. Launch craft "SSCX-01V01 Rosa Luxembourg"(the space shuttle)
2.Target and approach craft "SpSt-300km Dream Knitter"(the space station)
3.Try docking to any docking ports of the space station and you may find the bug(if it is) occurs