I just purchased Joytech Exceed Grip Pro. At first I filled it with 20mg/ml nic salt juice. When I tried to take a drag it worked for a second and when exhaling there wasn’t any vapour. I thought that it was because of the very strong juice and that I was unable to to take a drag for a longer than a second. But when I refilled it with another juice, I observed that after a second it just stops working. The cartridge is filled with juice. I bought it today and haven’t been able to take a single drag. It just doesn’t work for longer than a second. What could be wrong? On display it shows that the battery is full. Thanks in advance!