I can see the two pushrods binding with each other. they are tied close together but the two pushrod guides try to separate them when they are pushed which is causing a lot of friction and binding as they are entering the guides. you have no problem when it pulls back because the separation get greater. the loose end pushrod guides are going to cause trouble because the guides can move front and back which can cause a sag in the pushrod so they bend more then push in the space between the ends.

why do you need two push rods? with out knowing the whole setup you need to keep the two push rods rigidly fixed with the proper spacing so they can enter the guides freely. disconnect the push rod from both the servo and the rudder and see how tight the pushrods bind up when you push them by hand with nothing connected. I have seen spacing maintained by using a round dowel. three holes are drilled in the sides. two are drilled in the sides at the horizontal. the two rudder push rods are bent 90 to go into the holes and the rest of the pushrod follows the length of the dowel this provides spacing. the other hole is drilled on the top or bottom and has a 90 bent pushrod inserted but this rod goes forward and attaches to the servo. the dowel is covered in shrink wrap to hold the rods in and keep it together

ok split elevator that why two pushrods but they are binding getting into the guides.

looks like control horn from rudder will impact side of aircraft when the rudder is pulled. you might have to trim the bottom of the horn to allow movement of the rudder