For anyone still having issues,
I tried to replicate the issue and noticed two variable's that had a similar effect for me.
I have had no problems with my kanger subtank plus with air flow wide open( I inhale hard), chain
vaping in TC mode with japanese cotton wicks, a single 28g ni200, 0.08/0.07ohm coil, but have been running a twisted (the wire wrapped around itself using a drill) 28g ni200, 0.05ohm coil, dont want to quote wraps as I can't remember and am not willing to pull it apart again!.... but if you really want to know when I recoil it I will let you know. The only reason I have had to stop at any time is because of the tank heating up WAY too much due to chaining.
The twisted coil has been giving me a hot vape at 500f and nice vape at 470f ( I always have the watts at max and let the mod regulate it from there) with above average clouds and flavour. It does fluctuate/pulse the heat over a 8 second pull but this is what it is supposed to do!
All test's were done at 470f and max watts using kanger subtank plus rba with air flow wide open and twisted 28g ni200 0.05hm coils.
So I over wicked covering my
juice holes and had a few ihales on it and this resulted in a cold, low to no vapor inhale and "protection" warning, the first inhale was OK but went downhill after that
I underwicked and had the same issue, as well as unburnt juice spitting into my mouth
I tried the same setups on a sigelei 75w TC and low and behold the over wicked one worked, but only for 3 to 4 seconds and then tc protection kicked in, tried again and same result with a slight off taste so stopped.
The under wicked one did the same 3 to 4 second pull and then came the off taste just befor a burnt wick
So different mods work differently, maybe the mini is a little more sensative to minute changes in tempriture, so saying it worked on "insert brand here" but not on the mini isnt really aples for apples.
When I rewicked and went back to my mini I had a sinking feeling as the vape was cold and non existant!!!!! How do I fix this??? I know lets check the wick, I pushed it clear of the juice slots and it improved, but not to what I know it should be, hmmm I then took off the tank and checked the pin on the tank, wiped it and cleaned and pushed the pin on the mini in and out a couple of times and BAM Im back where should be,
So my advice is three fold,
1) Correct wicking is crucial for preformance and only trial and error has been my guide for my setup
2) Contacts are importent, check your post on you mod and tank are clean and move easily and have not been jammed into place ( I think what had happened to mine was I removed the tank when the mini and tank were hot and the pin on the mini stuck in place and wasnt moving freely and not contacting properly)
3) As for pre built coils thay are always hit and miss due to mass production and infrequent quality control testing, I have always had issue getting regular experiences from pre made coils on all tanks Ive had
If you are 100% sure all of these things are not causing the problems then Id be asking for a repair/preplacement
Hope this helps someone.
Peace