Purchases with purchase unit factor only adds one stock unit

[RillAlv]

Example product settings in grocy: Quantity unit stock: Bar Default quantity unit purchase: Pack Factor purchase to stock quantity unit: 4

Purchasing one of this product (1 pack) should add 4 bars to stock, however it only adds 1 bar to stock. The 'Factor purchase to stock quantity unit' is being ignored. I have tested this with multiple product entries, and all only added at 1:1 factor.

Version Info: grocy 3.3.1, app 2.4.2