Please refer to this plan:
The initial section of the road to access the service area was marked as one way, yet it was supposed to be used for both entering and exiting the area. Thus we'd be able to enter but not exit the area and this is what pointed us to create a different route.
We've had the map corrected in openstreetmap.org but it may take a week or two before these edits are live in ABRP.
Thank you for the link, it looks like the point isn't accessible the correct way thus we do this silly attempt. We'll look into what's barring us from going the correct route.