MinimOSD inconsistency problem

Hi, i fly fine with my osd execpt for one problem: i get the OSD view only if i restart the osd 3 times with the copter powered.

I have an IRIS+, micro minim osd and Mi600s VTX that has a +5v output wich power the osd (no need for the 12v with this board).
I have to unplug the vtx/osd power three times to get osd working. Otherwise i get only the gopro image.
During these reboots, i get the welcome minimosd screen and osd is seen (with correct data) only for a second or two then desappear leaving me with only the gopro video.
I dont think is a connection problem because it get ok after 3 (or rarely 4) osd/vtx power cycles and then is rock solid even if strong manuovre.

any hint?