Odroid N2+ no wifi with RTL8821CU USB adapter

It’s your hardware what is might “programmed differently”:

[    5.265501@2]- Empty EFUSE with unknown REF type!!
[    5.265501@2]- 
[    5.265501@2]- RTW: ERROR please program efuse or specify correct RFE type.
[    5.265502@2]- RTW: ERROR cmd: insmod rtl8821cx.ko rtw_RFE_type=<rfe_type>

Try with this test image and the USB dongle plugged in:

rmmod 8821cu
dmesg -c
echo 'options 8821cu rtw_RFE_type=7' > /storage/.config/modprobe.d/8821cu.conf
modprobe 8821cu
dmesg | paste

The Odroid version shows:
rtw_RFE_type=34

I was also reading they provide a extra driver for this stick. You might request the sources as it should be under GPL. They did modify the driver so the stock is working with it.