I guess gun quality is less tied to price than is generally thought.
If you read about the 320 design, and why the Army chose it over the Glock, you will see it has great advantages for the army but is relatively new as a concept.
Example: the “gun” is the trigger group and receiver, while the frame, barrel, and pretty much everything else can be swapped out for grip size, caliber, mag capacity, personalizing, etc. Means the army can maintain with a relatively small inventory a gun that can be used to meet the needs of post guards, special operators, small female hands, or 6’6” 280 lb soldiers alike.
Being the new design on the block, without the years or even decades of field experience like Glock, it is not surprising that a defect slipped by and a recall warranted.