Had probs to install VOS coming from UT.
Used on a Linux Mint PC UBports installer.
Only installing the TWRP3.3.0 got flashed and not VOS.
As wiping doesn't work in TWRP as it had no write privileges on system flashing doesn't work either.
So I've sideloaded the VOS .zip file via TWRP sideload option which worked.
Afterwards the IMEIs were gone.
https://rubencarneiro.github.io/rubenca ... EI-Repair/
Being more specific I only needed to do this:
Reboot again to recovery. Now on your computer do adb shell
And the following commands:
mount /dev/block/by-name/nvdata /mnt/vendor/nvdata
restorecon -R /mnt/vendor/nvdata/ -v
umount /mnt/vendor/nvdata && sync && reboot
It worked perfectly.