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

Was that from a primary source or from a summary of one?

BethLabQueen said:

My HPLC chromatogram analysis for certificates of analysis — I sent my batch to Janoshik and here's what the results showed: Main peak retention time:…

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. Pushing back on the consensus forming here. Consistency is not the same as correctness, and a board that agrees with itself quickly is usually agreeing with the first person who sounded certain.

BethLabQueen said:

My HPLC chromatogram analysis for certificates of analysis — I sent my batch to Janoshik and here's what the results showed: Main peak retention time:…

Right, and the exception is worth naming rather than left implied, because the exception is where people get into trouble.

BethLabQueen said:

My HPLC chromatogram analysis for certificates of analysis — I sent my batch to Janoshik and here's what the results showed: Main peak retention time:…

Genuinely useful, thank you. I had the facts and not the framework. I will report back once I have actually tried it.

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

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.