Low flow has many causes
High resin viscosity, high filler, degradation, temperature off-window and poor lubrication can look the same on the gauge. A flow modifier is a candidate — not an automatic diagnosis.
Plant script
Confirm matrix (PE/PP/PA), process (extrusion vs injection) and whether the issue is fill, gloss or cycle. Then compare wax/lubricant vs flow modifier in a short trial.
Next step
PE/PP, PA and injection landings tie to the SKU. Talk to Plectus engineering for a sample and validation on the real mold/extruder.