Hey guys! So I have a question about my RX200S. I have a 0.25 ohm coil in it, and vaping at 70W. When I hit the fire button, you can hear the hissing crackling sound, but then it slowly starts to get quieter and quieter after like 3 seconds, almost like it's dying down. Why is it doing this? Are my 18650s starting to give out possibly? I'm using Samsung 25Rs.