First off, I think you should try moving the coil from the Luxe XR Max into the Armour GS. If it works this way, then at least you’ll know that the other coil is toast.
Unfortunately, I don’t have many more tips, maybe the airflow setting. I had 2 Luxe XR Max devices, nothing special, I didn’t notice a big difference in flavor between the coils. I don’t have long-term experience with the Armour GS device, I might have used it for 2 days.