What’s your current Azerite Neck Level? AMR also checks your Azerite Level when optimizing to get the most optimal gear you’re currently able to use.
Higher items require higher Azerite levels so you’re most likely at a point where you’d get an additional trait from the LFR item but not the Normal one.
For the Gridrunner Galea (and every other similar helmet) the requirements are 13, 17, 21, 25 for the LFR version but 16, 19, 22, 25 for Normal.
You can change your Azerite Level when editing your character’s details using the menu (“hamburger”) button to the left of your character name.