Hello Unfortunately I have some day off at the moment. Model is very simple. I only wanted to check the heat transfer between the border of two simple elements. This was my main target, because on my more complicated model I have noticed that on the connection between two elements heat is only transported from element A to element B - I mean that element A is cooling element B but element B isn't heating element A - the clear border of temperatures is visible - straight line. I thought previously that problem would be in direction between SOURCE and TARGET of INTERFACES established by contact regions. Maybe the problem is in the method of calculation results displaying.
Maybe if you have time, you can draw two simple boxes (rods) with the connection on the common wall and try to show your results with two different constant temperatures assigned onto opposite walls.
Thank you.