I installed a new 20-amp GFCI in the kitchen which has two aditional download receptacles running off of it. When I test it with a separate “Commercial Electric” tester the GFCI trips immediately. All appliances plugged into the circuit work. Thinking it might be a defective GFCI, I swapped it out with another and it does the same thing. I checked and rechecked all wiring and connections and everything is wired as it should be. Bottom line is, only the tester trips that one particular GFCI despite it not tripping any of the others in the house. Any suggestions?
Edit: Maybe I didn't explain myself clearly. The GFCI is wired correctly, incoming feed wires are connected to the LINE terminals and the outgoing wires feeding two sockets downstream are connected to the LOAD terminals. The test button on the GFCI trips the unit as it should. It's the tester itself that is tripping the GFCI.