@Varana. It is not TF that assigns paths in the rather strange way. Such things are caused by serious flaws in a layout design. I have discovered also a small flaw in my design.. it’s the existence of the in fact unnecessary signal D. A long train that is stopped by that signal can create a deadlock at cross-over switch B.
The main problem of TS was that he didn’t find out how to create a situation that all problems for trains to drive to or from his depot are solved. In my example showed in my post before there are no path finding problems to the depot. And the green en red lines east of my cross over are separated by design, exactly working as intended my me.
In answer to your question (regarding the link to your picture) I have a simple answer. Also your design has critical flaws. Viewed from the driving direction, you have placed signals short after the passage of a switch, why? Knowing that signals situated just behind a switch are placed at a wrong spot belongs to the basic knowledge of layout design in this game. Further, you have placed two way signals at one side along the route and at the other side one way signals, what is the meaning of that?
Below is a picture of an example I have created for you. The flaw in the mainline in your design is fixed by proper placed one way signals at the correct spots, and my trains can drive from and to the depot from both directions. Is this the situation you wish? Oh.. the red route on the main line can also be achieved by placing two way signals there, creating the same result.. but I never use two way signals if not needed.
