FreeNAS-11.3-U5 update.failed - no such table: auth_group

[soildebt]

I've regularly been trying to update an 11.3-u5 system to TrueNAS 12.0 and I think I've so far tried RELEASE, U1, U3 and U6 all without success and basically the same behaviour. My latest attempt to upgrade to 12.0-U6 results in the following database update error:

Code:

root@truenas:/data # cat update.failed
+ python3 -c 'import os; import middlewared; print(os.path.dirname(middlewared.__spec__.origin))'
+ cd /usr/local/lib/python3.9/site-packages/middlwared
+ alembic upgrade head
/usr/local/bin/python3.9/site-packages/pyVmomi/Version.py:26: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if isLegacy or ns is "":
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade e49fadd7285d -> 0d545b21e189, Drop Django tables
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1247, in _execute_context
    self.dialect.do_execute(
  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/default.py", line 590, in do_execute
    cursor.execute(statement, parameters)
sqlite3.OperationalError: no such table: auth_group

I don't recall doing anything unusual with groups on this system, I believe all I've done beyond the defaults is add a single group manually using the web UI. I was hoping a later 12.0 release might eventually take care of it if I waited, but alas it doesn't seem like it. Does anyone have any thoughts on how to troubleshoot from here?