Why has ARAX API command /PubmedMeshNgd stopped working?

[saramsey]

So, in ITRB TEST, this API command works as expected,

sramsey-laptop:~ sramsey$ curl -X 'GET'   'https://arax.test.transltr.io/api/arax/v1.4/PubmedMeshNgd/PTGS2/acetaminophen'   -H 'accept: application/json'
{
  "response_code": "OK",
  "value": 0.6197083479333347
}

but on arax.ncats.io production, it does not:

sramsey-laptop:~ sramsey$ curl -X 'GET'   'https://arax.ncats.io/api/arax/v1.4/PubmedMeshNgd/PTGS2/acetaminophen'   -H 'accept: application/json'
{
  "message": "Term 1 'PTGS2' and Term 2 'acetaminophen' not found in MeSH",
  "response_code": "TermNotFound"
}

anyone know why? I wonder if this API command is tested so infrequently, some months-ago code commit broke it and we never noticed?