Ended up finding a workaround to this problem, which was to use the built in 'shadow' functionality in the makeIcon() function to combine the pin and icon into a singular icon.
Example below:
syringe = makeIcon(
iconUrl = https://www.svgrepo.com/show/482909/syringe.svg,
iconWidth = 30,
iconHeight = 20,
iconAnchorY = 35,
iconAnchorX = 15,
shadowUrl = https://www.svgrepo.com/show/512650/pin-fill-sharp-circle-634.svg,
shadowWidth = 50,
shadowHeight = 40,
shadowAnchorY = 40,
shadowAnchorX = 20,
popupAnchorX = 0.1,
popupAnchorY = -40
)