You might have coil eating juice. Your coils could just be a bad batch but smok coil are kind of notorious for not being long lasting especially some tanks and coils, and unfortunately bad coils do slip through, and etc. You could try other coils than Smok coils in that particular tank there are many to choose from.
Sometimes loosening up the cotton in some of the coils which may be partly clogged and hence, not wicking well and efficiently in a particular batch or type of smok coil has been useful and etc.
Honestly if you like this tank but can't make any of the coils for it work and you don't like them and they aren't working and you've tried all you can, well try any of the myriad non proprietary coils in it and continue to use the tank, no point continuing down a dead end road when you have like, options and etc.
Anna