This is known issue to me. The software thinks that any decimal amount represents currency so it automatically formats quantity as currency. You can remove decimals manually so it doesn’t show on print out to customer if it’s a problem.
Keep in mind, qty column is relatively new feature and it exposed some bad assumptions I made about the software early on. My intention is to correct this before it becomes even more obvious as I keep adding more features.
This has been now fixed in the latest version (13.12.3)