New Arc Fault Circuit breakers installed. On 1 circuit all wiring & circuitry checks out good. Circuit stays alive when nothing plugged in. Circuit stays alive when all devices plugged in so long as they are not on. However, whenever a device is plugged in & it is switched to on, the arc fault breaker trips. It does not matter which device it is as every device has the same impact, one at a time. Breaker changed out with known to be good breaker, same results. Once a lamp, fan, electronic device, surge protector alone, you name it is plugged in & turned on, the breaker trips instantly. Common part of circuit is not shared with another circuit & returns to the common bus bar by itself.
Any detailed thoughts & solutions?
Thank you

Can we please have some pics of the breaker's installation. Also, what is the static load of the circuit (15 or 20 amp)? What is the AWG of the cable being used in the circuit?

You say the entire circuit look good, how did you ascertain that? Did you pull all of the outlets along the circuit and verify the condition of the cable and connections?

Static Rating is 20 Amps.
Voltage is 120 VAC
AWG is 12 ga.
Circuit holds with all loads connected but not on (individual)
Circuit holds with complete load side disconnected.
Curcuits tests appropriately.
Visiual inspection of wiring, connections, & other devices is good.
Circuit holds with all loads disconnected (individual)
Circuits trips immediately when load devices turned on.
Examples of devices are older model (85 possibly) non tube type TV, floor lamp, fan/airpurifier type device, SATV receiver, isolated surge protector, stereo receiver, dual cassette deck.
Other known to be good AFCI breaker tested on circuit.
No phot available, but photo would should proper Square D QO AFCI breaker installation installed above two other AFCI breakers on bus with breaker nuetral connected to independent nuetral bus & incoming nuetral & hot from circuit homerun connected to AFCI breaker accordingly.
No apparent shared nuetral load.

They will trip like a GFI as well, If the circuit sees an unbalanced load like 2 circuits sharing a neutral, it will trip.
Hot and Neutral MUST draw same amount of current.
Neutral may be touching ground somewhere.
If hot was touching ground, the breaker should trip.