Just in case this helps with Nano clones. I have just been given a box of 5 Nano clones advertised as :-
[MINI carte de développement PCB USB Nano V3.0 CH340G FT232RL 5V 16M, Micro-contrôleur pour arduino].
Non of them initially worked but after much brain wrenching, finally they now all work.
I have not downloaded any new drivers or changed to any previous Arduino IDE.
I am running an iMac with Catalina 10.15.7 and Arduino 1.8.16.
In tools, I have set Board to "Arduino Nano". Processor to "ATmega328P old boot loader".
Port to "dev/cu.usbserial-1440". Programmer to "Arduino as ISP".
I then discovered that it was necessary to "reset" the Nano after "Compiling" the sketch and before "Uploading". I think that the "reset" was the all important thing to do.
Now all 5 clones work.
Hope that this helps anyone else who maybe contemplating ****.