Did you throw the others away? You can snap them off and put them on the longer style if you kept them. They are interchangeable. I take mine apart to re-wick and dry burn and don't pay attention to which ones the short stems were on when re-assembling. There is a slight difference in the vape between the long & short stem but it doesn't bother me.
I haven't had much luck with dry burning either type. The silica changes somehow after a dry burn and I can taste it in my lighter flavored liquids. I still burn the gunk off the coil but change out the wick to cotton instead of trying to save the original silica one. I bought some silica to play with but so far I really prefer the taste of the cotton ball wicks.
I get the same thing. I've been cleaning and dry burning the heads for months now. Sometimes they come out fine, other times they don't. I found that rinsing them with water after dry burning them helps to remove whatever dry burning does to them.
You said you change your wicks to cotton, which makes sense. But isn't some of what changes by dry burning done to the coil itself (because it's wrapped around a silica wick), or do you somehow manage to remove the silica wick from within the coil and replace it too?