I puchased a Mini3 Pro bundled to a DJI RC from the Italian DJI website, I paired them together and I could fly the drone without problems. I then purchased a second hand RC-N1 (from UK) and tried to pair it to the same Mini3 drone with no luck: they simply ignore each other...before concluding that I purchased a faulty second hand unit: was I supposed to unpair the other RC before connecting the RC-N1? Could a country mismatch between RC-N1 and the Mini3 be blocking the pairing procedure? Is there something else I should be aware of in pairing the second RC?

because i don't have the drone in hand right now, i am generalizing.  you can only connect one remote to one drone at a time.  if you drop your remote in a lake, it would make sense to me that you do not have to unpair before you buy another remote and pair it and use it.  doing so will automatically break the connection with the previous remote since only one remote at a time to one drone.  just make sure the sw is up to date in the remote.

This is going by other DJI drones, I do not have a Mini 3 Pro.
I find it is NOT necessary to "unpair" one controller before pairing the 'replacement' controller. The act of pairing the 'replacement' controller to the drone automatically "unpairs" the first controller EVERY time.
Are you following the  procedures shown in the youtube videos, including any button press and holds on the drone itself? Unfortunatelty I didn't find a video that dealt solely with pairing so you may have to skim irrelvant stuff until you find the good stuff.
With the RC-N1/RC231 there is also a button pressing sequence on the controller that will send the controller into pairing mode irrespective of whether or not  a screen device is attached. I swap RC231's between Mini 2 all the time using that.

Where things may get more complicated for you is if the either controller was bound to the relevant DJI accont or the drone etc. if so others will have to address the complications.

I also tried to pair a brand new RCN1 and it was a real pain to get them to pair after many attempts I managed it through the normal channels. And if you go back to using dji rc you will most likely experience the same thing over again. There is a bug and its in the pairing not the remote.

I also tried to pair a brand new RCN1 and it was a real pain to get them to pair after many attempts I managed it through the normal channels. And if you go back to using dji rc you will most likely experience the same thing over again. There is a bug and its in the pairing not the remote.

hallmark007 Posted at 8-1 13:51
I also tried to pair a brand new RCN1 and it was a real pain to get them to pair after many attempts I managed it through the normal channels. And if you go back to using dji rc you will most likely experience the same thing over again. There is a bug and its in the pairing not the remote.

Thanks a lot: I will keep on trying to pair RCN1 via normal channels hoping to succeed sometime soon...  

Hi there. Thank you for reaching out. Currently, this function is unavailable but we'll forward this feedback to our developers. After the evaluation of the engineers, significant suggestions or requests will be implemented via the firmware update, app update, etc. For any updates, please stay tuned to the latest news on our DJI official website at www.dji.com. Thank you for your valued support.

DJI Paladin Posted at 8-2 03:01
Hi there. Thank you for reaching out. Currently, this function is unavailable but we'll forward this feedback to our developers. After the evaluation of the engineers, significant suggestions or requests will be implemented via the firmware update, app update, etc. For any updates, please stay tuned to the latest news on our DJI official website at www.dji.com. Thank you for your valued support.

Dji Paladin, which function are you stating it is not available? Do you mean that it is not possible to switch to RCN1 after pairing  MINI3 to DJIRC?

Oversampling Posted at 8-2 04:13
Dji Paladin, which function are you stating it is not available? Do you mean that it is not possible to switch to RCN1 after pairing  MINI3 to DJIRC?

Switching between remotes is possible, as demonstrated by Hallmark's post.

I assumed Paladin got hold of the wrong end of the stick and thought you wanted a dual control setup as is available on some DJI drones.
There, one controller is designated as the "primary" and the other the "secondary", they can be connected simultaneously but the primary has precedence, or singly. The secondary has restricted access to app menus. (M2P/Z).

Sean-bumble-bee Posted at 8-2 06:34
Switching between remotes is possible, as demonstrated by Hallmark's post.

I assumed Paladin got hold of the wrong end of the stick and thought you wanted a dual control setup as is available on some DJI drones.

Thank you Sean, that makes sense.