clone collections pre-transformations, otherwise we bork everything
@@ -551,7 +551,7 @@ class BIDSStatsModelsNodeOutput:
# apply transformations
transformations = self.node.transformations
if transformations:
- tm.TransformerManager().transform(coll, transformations)
+ coll = tm.TransformerManager().transform(coll.clone(), transformations)
# retain only variables listed in 'X', and skip level if none are left.
tm.Select(coll, var_names)
