Thanks for reporting!

Regarding last case, you should be able to disable power anyway using uhubctl -l 2-1 -p 1 -a 0 -r 100. Try increasing -r option until it starts working.

Thanks @mvp, I tried with -r 1000 and it has no effect.

Thats weird, oh well... I guess you still have more or less working option of plugging external hub to ports 2 to 4.

It did not work for me. I had to do this instead
echo '2-1' |sudo tee /sys/bus/usb/drivers/usb/unbind"

Edited:
Actually, now uhubctl -l 2-1 -p 1 -a 0 is working on my jetson nano. I did not get what I changed.

What I am looking for is single port power switching that apparently Nano does not allow that due to the fact that all USB ports are ganged with each other as in raspberry pis. Any solution for that is appreciated.