I just updated my OP9 Pro via OTA from 4.0 to 4.1. After reboot I noticed I had an “Orange” level warning me that my bootloader is unlocked during the POST splash screen.
Hadn’t actually checked manually if the bootloader was relocked after doing the sideload of 4.0, and I did not see any instructions to re-enter into fastboot to use the “fastboot flashing lock” command at the end of installation.
Now it is a little too late for me to go back and relock my bootloader as this will wipe out all my personal settings/apps/files.
I am requesting that any further updates/ROMs released automatically relock the bootloader.
I will have to manually create a backup and reload everything if I want to have a locked bootloader again.
Once upon a time, bootloader relocking was possible on OP9; but began to fail since a certain stock firmware update. Maybe this will be fixed by OnePlus in the future, who knows. Even in that case, it would be dangerous to lock bootloader, as an issue that once happened could happen again with subsequent firmware updates. We could envisage it, if the last (end-of-life) firmware solved the issue.