Hmm strange, oppo australia was able to downgrade my device to a.41 from c.76 ukeeI just got back from the service center. After 1 hour of discussion they showed me on the pc the firmware available for the flash and they are Tim c73 "generic" and c73 Vodafone. And thanks to Edward Newgate who supported me, unfortunately I don't think there is a solution. I'm stopped at c75 installed thanks to nguyenfortunato with the december 2021 patches. The center can no longer do anything, so now with this version the gps, bluetooth and 5g no longer work, and this is just to begin with. They applied to oppo to replace the motherboard, but it seems Oppo doesn't want to know. I'm in a dead end.