So I own a eleaf iStick Pico for 3 months now and I faced a problem I cant solve. Everything was normal until my vape started to make kind of a hissing sound after I stopped vaping (when I release the button) it eventually started to taste like burnt. So I decided to disassemble my tank and clean it. Didn't solve. So I used a new coil, primed it properly as usual, it is better now. But still makes the hissing sound and doesnt release that much smoke. Any suggestions? Thanks in advance 