Adding the clinical framing, because it changes how the question reads. The useful move here is to separate what is established from what is widely repeated. Those two sets overlap less than the confident tone of most write-ups suggests, and the second set is where nearly all the disagreement on this board comes from.

That is the short version; the long version is somebody else's post.

lisa_labSD said:

The useful move here is to separate what is established from what is widely repeated.

Adding a me-too, because a thread of one person's experience is not much use. The detail I would add is minor and it is already implied above.

lisa_labSD said:

The useful move here is to separate what is established from what is widely repeated.

There is a second half to this that has not been said yet. Take it one variable at a time. Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent argument can untangle them after the fact.

The figures, for anyone assembling their own picture. 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.

A narrower follow-up, since the general answer is now clear:

How would you tell the difference between that and the alternative explanation?