NurseKim_ATL said:

It helps to ask what evidence would change your mind before you look at any.

Coming at NurseKim_ATL’s question from a different direction. Whatever the answer turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, and invite the correction. That is slower than asserting, and it is the only version that survives being wrong.

OP back with an update, since a thread like this is useless without one.

For the archive: it took about six weeks rather than the two I expected, and the difference between those two numbers was the whole of my problem.

Following on from NurseKim_ATL — and this may be the naive question:

How long did you give it before you decided it was working?

Admin said:

For the archive: it took about six weeks rather than the two I expected, and the difference between those two numbers was the whole of my problem.

This is where I part company with the consensus forming above. Pushing back on the consensus forming here. Consistency is not the same as correctness, and a board that agrees with itself quickly is usually agreeing with the first person who sounded certain.

Admin said:

For the archive: it took about six weeks rather than the two I expected, and the difference between those two numbers was the whole of my problem.

Right, and the exception is worth naming rather than left implied, because the exception is where people get into trouble.