DanielChem_CHI said:

My experience ordering cross-border ordering internationally: I've ordered from an Australian compounder.

I read this differently from DanielChem_CHI, on substance rather than tone. Import rules are jurisdiction-specific and this board keeps giving US-shaped answers to non-US questions. What is a personal-import allowance in one country is a controlled-import offence in another.

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.BariatricHTX said:

Import rules are jurisdiction-specific and this board keeps giving US-shaped answers to non-US questions.

There is a second half to this that has not been said yet. Order of operations matters more than any single choice here: establish a baseline, change one thing, wait long enough for it to express itself, then measure again under the same conditions.

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

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

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

Late follow-up. I did not do what was suggested, I did something adjacent, and it worked; posting the difference in case it matters to somebody.