well just fix the index issue locally
@@ -1897,7 +1897,9 @@ class CovariateParameterMappings:
Xs = {}
for param_name, transform in self.mappings.items():
if isinstance(transform, formulaic.formula.Formula):
+ index = df.index
X = transform.get_model_matrix(df)
+ X.index = index
elif isinstance(transform, list):
if self.force_intercept:
df = self.add_intercept_col(df)
