Thanks again @balbes150for all the help and the great work!
I managed to boot and to configure everything properly on my Mango Pi MQ with the headless image you built on 1st of December.
However after a while (a few minutes only), if I'm not active on the command line, the wifi goes on sleep and it's impossible to wake it back up, only a reboot can fix it. It seems like a driver issue?
Am I the only one who experiences it? Do you have a workaround? Thanks!