Bootcamp option missing

The bootcamp partition still shows up in Disk Utility and all of the Windows files appear ok (I'm using the latest version of Tuxera NTFS (dated 2018-01-25) to mount NTFS disks under Mac OS).

This is not a good idea. Tuxera (and all similar products) interfere with Windows booting. Can you temporarily uninstall/disable and check if you can see Windows in System Preferences -> Startup Disks? If you can, select it and try to boot from it.

The output of diskutil list is:

>diskutil list

/dev/disk0 (internal):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                         2.0 TB     disk0

   1:                        EFI EFI                     314.6 MB   disk0s1

   2:                 Apple_APFS Container disk1         1.9 TB     disk0s2

   3:       Microsoft Basic Data BOOTCAMP                96.8 GB    disk0s3

This looks like a standard configuration on APFS.

Strangely enough, I can't use the gpt command on the disk:

>sudo gpt -vv -r show /dev/disk0

gpt show: unable to open device '/dev/disk0': Operation not permitted

However, the gpt command works fine on a USB external flash disk:

sudo gpt -vv -r show /dev/disk2

gpt show: /dev/disk2: mediasize=2000398934016; sectorsize=512; blocks=3907029168

Temporarily, disable SIP and retry the command.

I can mount the EFI partition of disk0 and there is a Microsoft directory there.

This is a brand new machine and I haven't updated Mac OS at all so far (which was a potential problem I read about).

This is good to know.

I could redo the entire Windows install (I haven't begun to work on it yet) but frankly I'm concerned that this problem might recur and I'd really like to understand what the problem is before I go down that path as I don't want to encounter this again without knowing how to deal with it.

Let us first test removing/disabling Tuxera.

The Tuxera folks already know the issue. It is documented in https://www.tuxera.com/products/tuxera-ntfs-for-mac/faq/#Tuxera_NTFS_for_Mac_FAQ

Cannot set BOOTCAMP/NTFS drive as Startup in macOS High Sierra/Mojave after installing Microsoft NTFS for Mac by Tuxera

Apple doesn’t allow volumes mounted with third party file system drivers to appear in the “Startup Disk” preference pane. This is hard coded, and we cannot change it.

However there are numerous alternative methods for booting into Windows:

• Hold down the Alt/Option key during boot.
This brings up a boot menu where you can choose which volume to start your computer from

• Install the rEFIt boot manager for better control of the boot process

• Disable Microsoft NTFS for Mac by Tuxera (in NTFS for Mac Preference pane), unmount your NTFS volume with Disk Utility, and mount it again. Your volume will now be mounted with Apple’s read-only NTFS driver, and the “Startup Disk” preference pane will see it. Make sure to re-enable Microsoft NTFS for Mac by Tuxera afterwards

• Use the bless command line utility to set the disk as a default startup disk (see: man bless for more information).