Hhm Key Blanks

Key blanks are not approximately shaped. The milling down the blade has to clear the wards inside the keyway exactly, and a blank from a neighbouring profile will often enter the lock, travel most of the way in and then bind.

That looks like a fault in the lock and is not one. Read the code off the original key, or the lock body where it carries one, and match the blank to the code rather than to the look of the blade.