my subtank plus was find with the original rba head it came with with the juice channels,
but with the 'occ' coils and with the newer rba heads with the big holes it tends to leak
you must have a wicking problem then not enough wick or to thin around the juice holes to cause a leak dont sound right
i can chain vape mine for hours and go tank after tank causing the coil section to warm up and thin the juice like water and i have no flooding problems or leaking or dry hits
when i used to buy new occ coils the first thing i would do is pull the wick and redo it myself as i used to find them packed to tight and would not wick fast enough me
i dont buy coils anymore as i have plenty of used ones to rebuild now
and now my tanks are paying for themselves with what i save not having to buy new coils win win whats not to like about that