Copy the estimator instead

src/cellrank/estimators/terminal_states/_gpcca.py

@@ -573,13 +573,11 @@ def tsi(
             if cluster_key is None:
                 raise RuntimeError("`cluster_key` needs to be specified to compute TSI.")
 
-            # copy the `adata` object to avoid overwrites, as the estimator overrides some keys
-            adata = self.adata.copy()
+            # create a new GPCCA object to avoid unsetting attributes
+            # that depend on the macrostates, e.g. the terminal states
+            g = self.copy(deep=True)
             macrostates = {}
-            for n_states in range(1, n_macrostates):
-                # create a new GPCCA object to avoid unsetting attributes that depend on the macrostates,
-                # e.g. the terminal states
-                g = GPCCA(self.transition_matrix, adata=adata)
+            for n_states in range(n_macrostates, 0, -1):
                 g = g.compute_macrostates(n_states=n_states, cluster_key=cluster_key, **kwargs)
                 macrostates[n_states] = g.macrostates.cat.categories