HubSpot how to pull line item amounts every time

Hi everyone,
New to Make here! I am creating a scenario where I need to pull the quantity (and later the line item net price, but a latter issue) from specific line items in a HubSpot deal, add them together, and push them to a deal property. The trigger is the Amount of the deal being updated. Now, this works sometimes, but not always. I have a router step that splits the line items that may need to be calculated based on a property grouping them together. These are the following cases happening:

  1. Deal amount gets updated: route 1 quantity pulls and pushes through correctly; route 2 returns 0 despite there being a quantity value in HubSpot.
  2. Deal amount does not get updated: Scenario is run and pushes through the value 0 for quantity, even if value was determined previously.
  3. Quantity and amount changes of deal: scenario is run and pushes through the value 0 for the quantity, even if determined previously.
    In general, route 2 will always return a 0 even though the set up is exactly the same as route 1.

Given it can be a deal has no activity for a month or two, and this scenario will be run once a month, I especially can’t have data being replaced with 0 if not true.

Thanks for the advice in advance!