DeniseRN_TPA said:

There is a difference between no evidence and evidence of no effect, and this subject is one where the two get swapped freely in both directions.

There is a second half to this that has not been said yet. Start from the measurement rather than the conclusion. Almost every disagreement here turns out to be two people measuring different things and comparing the numbers anyway.

The figures, for anyone assembling their own picture. One habit that pays for itself: post the method alongside the number. A figure without its method cannot be checked, and an unchecked figure is how this community accumulates folklore.

Correct me if the detail matters more than I have assumed.

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

What did you change at the same time, and can you separate the two now?

hank_denver said:

One habit that pays for itself: post the method alongside the number.

Worth saying that the confident version of this is more useful to the person writing it than to the person reading it.

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

Update, and it is the boring outcome: nothing was wrong. The measurement I was reading had moved less than its own week-to-week variation, which somebody said upthread and I did not believe.