60w may be too high to start off with a new head.
Always start a new head off at a lower power like 10w to as much as 20w under the recommended and gradually increase over the first half tank or so, to ensure it is wicking correctly & to allow the head to break in without burning or scorching wicking.
You may not get a satisfactory vape during this process but it is better than ruining new heads quickly.
If you zap a new head with 60w it can easily scorch or burn wicking nearest/surrounding the coil, this reduces the wicking materials ability to hold liquid = leaking.
The recommended power ranges are just that, recommendations, always vape to what tastes best to you not a number.
Actually the recommended w ranges are more of a guarantee you'll be buying more replacement heads.
Are you using DTL inhale?
hard strong fast direct into your lungs inhale, hard like your trying to suck a golf ball through a garden hose, fast as in a few seconds of draw, or MTL smooth slower inhale.
Which head are you using?
The gt8 is more of a cloud blower type, needs non restricted wide open or very close to it airflow with a large amount of airflow being pulled through it.
Half open airflow is probably too restrictive for a DTL inhale without pulling too much liquid into the head that has no other place to go than out the airflow. This causes flooding & leaking.