If you're rooted, an update will not work without doing a local upgrade, for which you need the full 2GB+sized update full install file that is not yet available. A regular OTA won't work. Unfortunately the full firmware files for this NA/Global unlocked ROM have been extremely slow to get out to the public. OnePlus has been releasing firmware files for the EU & Indian ROMs, but for whatever reason the global ROM users such as yourself/myself/many on this thread are left waiting. So until that file gets dropped, the only way you're updating (short of converting to maybe the EU ROM) would be to completely unroot, relock your bootloader (which I believe will wipe the phone again), take the update...and even after you've updated, you won't be able to root I think, not without a way to pull the boot.img and patch it. If there's a way to pull the boot.img without the full ROM file, I'd love to be told how...I'd gladly accept being proven wrong here! So we're all sitting tight on 11.5.0.6, just awaiting the 11.5.0.8 file to drop, and hoping it doesn't take forever this time (it likely will). This is the reason this conversion guide was only for the EU ROM for some time, only updated once the full global ROM firmware file became available. Blah.