adding a docking port changes radial decoupler behaviour?

[DarkEye]

Hi,

I encountered a strange phenomenon. When adding a docking port to my rocket, the radial decouplers on another part of the rocket behave differently. 

This shows the correct behaviour: https://drive.google.com/file/d/1Ese7u7Nrm4Gc5VtbzBuJBTm4RJL9KjZE/view?usp=sharing

While this shows what happens if I add a docking port: https://drive.google.com/file/d/1jk02VYK-YxLPnFj7coArnxxNR50OEp_O/view?usp=sharing

I wonder what could be causing this. Otherwise, all is the same.

 

Ákos

[OHara]

I do not know why adding a docking port would change things, but I do know what is happening in your second image showing the problem.

KSP makes a (simulated) mechanical connection between the part you place and the parent part it was placed onto.  (The part that is highlighted by your mouse pointer when you place the new part, is the parent part.)  That means that placing parts gives you what people call a 'tree' of connections, with all the connections looking like branches with no loops.  So the boosters in your image cannot be connected to both decouplers; it appears the booster is connected to the lower decoupler.

The way to add more mechanical connections is to place an EAS-4 strut between parts.  Then you can have a more complicated net of mechanical connection, not limited to a tree.  Players often connect boosters in the style at right.