I have a sweet, sourdough, brioche-like recipe that I usually make with the French starter from
sourdo.com. My Ischia starter was at the head of the rotation, so I decided to use it instead. The Ischia was fully active, having been used during the past week for pizza and Tartine bread. After feeding, it expanded and bubbled normally.
This bread uses a very rich dough with butter, eggs, brown sugar, and honey. It would not ferment at all with the Ischia starter. I even cranked up the heat in the proofing chamber and it still showed no signs of life. I began to question whether I had actually put any starter in the dough. I made up a second batch increasing the amount of starter just to see what would happen. Nothing happened after 2 days. You would think that the high sugar content might enhance the activity of the starter, but clearly something in this dough completely suppresses Ischia.
I tried the same recipe with the French starter and all was fine. Some of these wild starters like Ischia seem to be limited to a pretty narrow range of conditions.