fix pytest

nicegui/elements/choice_element.py

@@ -25,8 +25,9 @@ class ChoiceElement(ValueElement):
     def _update_options(self) -> None:
         before_value = self.value
         self._props['options'] = [{'value': index, 'label': option} for index, option in enumerate(self._labels)]
-        self._props[self.VALUE_PROP] = self._value_to_model_value(before_value)
-        self.value = before_value if before_value in self._values else None
+        if not isinstance(before_value, list):  # NOTE: no need to update value in case of multi-select
+            self._props[self.VALUE_PROP] = self._value_to_model_value(before_value)
+            self.value = before_value if before_value in self._values else None
 
     def update(self) -> None:
         self._update_values_and_labels()