I almost always like, vape below the recommended wattage. I will say, I also prime my coils. LONG SLOW INHALES without the fire button at all you need capillary action to suck juice up into your coils. I have heard people say they sit their coil in the joose 3 days, they are still not getting capillary action. Then increase by oh, for me 2 watts or so until I reach a happy place.
It could indeed be your juice, but a well primed coil is a happy coil. Also, chain vaping in wattage mode is murder on your coils. I have a lot of setups at once as a)I like variety and b) well, if I chain vape like I do every morning, I am not overheating the coil. I also DIY and I don't use crazy high flavored juice. That can help as well. But if this is your only mod, to not kill your coils you will have to not chain vape. I get insane life on coils and I mean CRAZY. Because I care for them like my little coil babies and I don't chain vape.
You can try temp more for chain vaping if you have a TC capable coil and it also works, but I am not convinced you have one.
Good luck!
Anna