So the passage in question is Exodus 30:23.
A modern edition has been coming for over a decade, so the edition to consult is still Origen Hexapla : Field, Frederick from 1875.
The Septuagint translates the verse as:
Do thou also take sweet herbs, the flower of choice myrrh five hundred shekels, and the half of this two hundred and fifty shekels of sweet-smelling cinnamon, and two hundred and fifty shekels of sweet-smelling calamus,
The sweet-smelling calamus is the herb kaneh bosem whose translation is contentious.
The Hebrew word בשמים (bosemim, right?) has the note: Οʹ. ἡδύσματα. Ἀ. ἀρώματα. That is, the Septuagint translates it as “sweeteners” and Aquila as “perfumes”. But that’s the word rendered above as “sweet herbs”. The next divergence noted in the Hexapla is the reference to cassia in the next verse. Kassia is noted as an alternate reading; the Septuagint’s reading is ἴρεως, refering to the genus Iris (plant).
Because Origen did not supply an alternate translation for Kaneh bosem, it is likely that the other three translations rendered it the same way as the Septuagint.
The other translations, btw, were often more accurate than the Septuagint, but they were also later. If the knowledge of what the kaneh bosem was, whether calamus or cannabis or chamomile, had already been lost, then the other translations could well have just copied the Septuagint.