Fault 18 points to a brake issue. On your screenshot, BK Voltage is 0 and no BK of course.
Dragging or sluggish brake once warm? Does this unit even have a brake contact? IIRC, don’t these controllers utilize a Brake Board? I’m just going off of memory here.
Check over the BK relay for worn contacts, broken wires at the NO/NC connections and coil. Do you have voltage at BK+ and BK- when the unit actually makes a run? Does it meet the required voltage and Amps as indicated on the prints? (Brake Lift Voltage? Brake Hold Voltage?)