Joining object changes layout

I’ve started using OmniGraffle V. 5 which was installed on my Mac.

There is one particular behaviour which is annoying me. Whenever I try to join objects together, such as joining lines and shapes, the layout of my diagram changes suddenly.

All the shapes become stacked on top of each other and I have to used cmd-Z to undo. I cannot join lines and shapes due to this behaviour. I am forced to bring the line close to the shape but not actually connect it.

I would like to know if there a setting enabled in my application that is causing to happen. I have attached a photo for better understanding.

Thanks for help for this otherwise fine piece of software

The current version of OmniGraffle is version 7, quite a bit has changed between the versions - have you tried using 7? There’s a 2 week free trial.

It sounds to me like you have Auto-Layout on and need to uncheck it. There is a picture of the box to uncheck here: