diff --git a/starpilot/assets/model_manager.py b/starpilot/assets/model_manager.py
index f41febbc..26de0c0a 100644
--- a/starpilot/assets/model_manager.py
+++ b/starpilot/assets/model_manager.py
@@ -66,10 +66,12 @@ class ModelManager:
     self.params_memory = params_memory
     self.downloading_model = False
 
-    self.available_models = [entry for entry in (self.params.get("AvailableModels") or "").split(",") if entry]
-    self.model_versions = [entry for entry in (self.params.get("ModelVersions") or "").split(",") if entry]
-    self.model_series = [entry for entry in (self.params.get("AvailableModelSeries") or "").split(",") if entry]
-    self.available_model_names = [entry for entry in (self.params.get("AvailableModelNames") or "").split(",") if entry]
+    self.available_models: list[str] = []
+    self.model_versions: list[str] = []
+    self.model_series: list[str] = []
+    self.available_model_names: list[str] = []
+
+    self._load_catalog_from_params()
 
     self._ensure_model_params()
     if boot_run:
@@ -98,6 +100,12 @@ class ModelManager:
       return default_value.decode("utf-8", errors="ignore").strip()
     return str(default_value).strip()
 
+  def _load_catalog_from_params(self):
+    self.available_models = [entry for entry in self._param_text("AvailableModels").split(",") if entry]
+    self.model_versions = [entry for entry in self._param_text("ModelVersions").split(",") if entry]
+    self.model_series = [entry for entry in self._param_text("AvailableModelSeries").split(",") if entry]
+    self.available_model_names = [entry for entry in self._param_text("AvailableModelNames").split(",") if entry]
+
   def _set_model_param_keys(self, model_key: str | None = None, model_name: str | None = None, model_version: str | None = None):
     if model_key is not None and model_key != "":
       canonical_key = self._canonical_model_key(model_key)
@@ -313,6 +321,9 @@ class ModelManager:
       self.downloading_model = False
       return
 
+    # Refresh from params so long-lived workers pick up manifest refreshes done by
+    # a separate ModelManager instance before we validate the requested model.
+    self._load_catalog_from_params()
     version_map = self._model_version_map()
     model_version = version_map.get(model_to_download)
     required_files = self._required_files(model_to_download, model_version or "")