Adding the numbers, since they settle part of this. One practical note: write down what you did and when, before you need it. Reconstructing a timeline from memory three months later is how people end up unable to answer the one question that would have resolved it.

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

One thing that is still open after hans_munich’s answer:

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

SleepDoc_PDX said:

One practical note: write down what you did and when, before you need it.

Pushing back on SleepDoc_PDX here. This treats a plausible mechanism as a demonstrated one. Plausible is where you start looking, not where you stop.

SleepDoc_PDX said:

One practical note: write down what you did and when, before you need it.

That is right, and it stops being right at the edges. The general case is well behaved; the interesting cases in this thread are all at the boundary where the general case breaks.

SleepDoc_PDX said:

One practical note: write down what you did and when, before you need it.

This answered a question I did not know how to ask.