From what I can see, it could be the source of the wire that makes a difference, but there's dozens of sites/threads/discussion that I've found that a LOT of people have the exact same issues, where, yes, SS does do TC, BUT it spikes in an unbalanced way and isn't as stable as NI200 is. Even TI has issues.
I've been building TC coils for over a year with NI without any issues at all, I found that TI didn't work well and gave me a much more pronounced metallic taste so I stopped trying, got my hopes up with SS, got a few spools, and been trying several times with it and every time, it behaves weirdly, like an instant burn and playing with wattage, it's like too low wattage and nothing, a few clicks up and bam, too much again and the vape is very nasty with an acrid taste. Using it in normal wattage mode, no problem though.
And yes, I didn't just use the basic SS setting on my mods, I've only tested using the programmable TRC tables, with 316l at the recommended 88 (up to 94).
And this is on various tanks, so not just due to one that might be "off" for the connection, and also tried two gauges of wire, with the same results.
Again, I spent a few days researching it, and found that this is a very common issue for a lot of people.