Roche Diagnostics is the company that makes the immunoassay analyzer used to measure serum progesterone as well as many other hormones that use the ECLIA methodology.
On the Labcorp website for the progesterone test in the first footnote they list the package insert for the reagent used for the test. If you do a search for that insert you will find that it comes up as the Progeterone II reagent. I found a copy in Portugese:http://www.biodinamica-ltda.com.br/documentos/elecsys/fertilidade/Progesterone%20II%2012142236001%20V8_pt.pdf
You don't need to understand much Portugese to go to page 3 where they list the reference range for men to be 0.2 to 1.4 ng/ml which, if I remember right, is the old Labcorp range, or close to it. Note that the median level is 0.6ng/ml, but the sample size is only 33.
A month or 2 ago Roche came out with the new Progesterone III reagent. A copy of the package insert is here, in English this time:https://pim-eservices.roche.com/eLD/(S(pjfwzwolefl50reliuwzkbzs))/cn/en/Documents/GetDocument?documentId=f3cd9bf4-2b61-e511-f1bd-00215a9b3428
If you go to page 3 you can see that the reference range has changed considerably. From <0.05, basically undetectable, to 0.149 ng/ml, with a median value of <0.05. The sample size this time was 147.
This is pure speculation on my part but I would guess that Labcorp switched to the new reagent but didn't update the footnotes on their webpage yet.