My Boge 3.0 ohm carto in a mini sub tank on a Provari is making a creaking sound for a second after I vape it. Ever had this happen? It just started doing this a few hours ago. I'm using 100%VG juice and there are 4 holes in the carto made with a saddle valve (so they're pretty small). I've had this carto in my tank for about a week and refilled about 3 times.