You can try to run: fastboot oem 8901_unlock
Thich seems to be able to unlock a device where oem unlock fails, see e.g. this topic: [Solved] HUGE problem - Boot and update to Android 10 or search for 8901_unlock in the forum.
You can try to run: fastboot oem 8901_unlock
Thich seems to be able to unlock a device where oem unlock fails, see e.g. this topic: [Solved] HUGE problem - Boot and update to Android 10 or search for 8901_unlock in the forum.