InsuranceTom said:

Most of what circulates confidently in this community traces back to one summary of one study, and the qualifier was dropped somewhere in the third…

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. Filing an objection on the n=1 problem. Personal experience is genuine evidence about one person and very weak evidence about anybody else, and this thread keeps promoting the first into the second.

Adding the numbers, since they settle part of this. If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way. Most of the apparent contradictions in these threads dissolve at that step.

Dr.NateNeph said:

Personal experience is genuine evidence about one person and very weak evidence about anybody else, and this thread keeps promoting the first into the…

Adding the part of the answer the thread has not reached. 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.

Following on from tampaLisa73 — and this may be the naive question:

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

Closing the loop on my own question.

Following up because I said I would. I changed one thing, left everything else alone, and waited the full interval before looking. It resolved, and I cannot prove which half of that did it.