Usb Mtp Per Default? How To?

Nov 30, 2017
unlocked, developper option .. usb ... use MTP
fine until one does unplug/replug the phone since then it falls back to charging which makes the developper setting pretty senseless.
Any idea what I might do wrong here? I do wonder since for example changing ARVCP version from 1.4 to 1.5 remains permanent.
Poor enough Android removed the setting to define which usb mode should be default.
In case the developper mode setting loosing the setup is "works as designed" anyone with a clever idea on how to make MTP permant, surving unplug/replug aswell as power down / restart of the phone?
Thanks in advance