SMOK vape pen 22 issue

so i've had mine for about 2 months now and its been doing some weird shit over the past couple days. when i take a hit it usually doesnt make that kinda bubbling liquid sound (idk how to describe it) and half of the time its a dry hit (tastes burnt) i've tried putting in a new coil but it's still doing the same shit. also it doesnt produce as much vapor as before this problem started. help !