Putting encoded pattern in dual interface without integrated circuit (24) doesnt let you craft cables.

and with blocking mode that ignore content of the target inventory it just doesnt work.
removing integrated circuit, items apear in interface

blocking mode is to not output when there is contents in target container. so you should turn off the blocking mode if you put the circuit in assembler

it is turned off (see screenshot)

hmmmm. then try to disable the input filter of the gt machine, shift + right mouse click to machine with screwdriver

when machine have an item in any input slot, dual interface doesnt put items in, but fluids does
try with that mode:

each side with screwdriver just change input behaviour.
when i remove circuit from machine, dual interface put items to machine, but if circuit already in machine it doesn't

do you hold shift?

yes.
GT 5.09.28

figure it out. it is a gt5u side bug Blood-Asp/GT5-Unofficial@a625088, updating to 5.09.31 should fix that.
gregtech-5.09.31.zip
unzip this