I've been using DCTs for a while, both US made ones and China made ones. Each DCT usually lasts me for 2 weeks as I usually take very hard drags and vape alot.
Anyway DCTs tend to leak when the wick is getting burnt out. The wick is usually all fuzzed out that it does not hold the juice in as well as before. Try cleaning the top of the carto with some tissue and try
vaping again. If you start to taste alittle burnt smell on your DCT, it probably is about to die. Just throw it away and vape another one.
DCTs are meant to be used and thrown. No point having so much fuss if you've tried everything and it still doesn't work out. Typical lifespan of a DCT for an average person is 3weeks to 1month.
All the best!