diff --git a/src/gui_qt/data/datawidget/datawidget.py b/src/gui_qt/data/datawidget/datawidget.py
index 34c19d9..45ffc52 100644
--- a/src/gui_qt/data/datawidget/datawidget.py
+++ b/src/gui_qt/data/datawidget/datawidget.py
@@ -532,11 +532,14 @@ class DataTree(QtWidgets.QTreeWidget):
     def uncheck_sets(self, sets: list[str]):
         self.blockSignals(True)
         iterator = QtWidgets.QTreeWidgetItemIterator(self)
+        self._checked_sets = set()
         while iterator.value():
             item = iterator.value()
             if item is not None:
                 if item.data(0, QtCore.Qt.UserRole) in sets:
                     item.setCheckState(0, QtCore.Qt.Unchecked)
+                else:
+                    self._checked_sets.add(item.data(0, QtCore.Qt.UserRole))
                 iterator += 1
         self.blockSignals(False)
 
diff --git a/src/gui_qt/fit/fit_forms.py b/src/gui_qt/fit/fit_forms.py
index 624b13d..4b696c5 100644
--- a/src/gui_qt/fit/fit_forms.py
+++ b/src/gui_qt/fit/fit_forms.py
@@ -77,9 +77,11 @@ class FitModelWidget(QtWidgets.QWidget, Ui_FitParameter):
         if bds is not None:
             self.set_bounds(*bds)
 
-        self.fixed_check.setCheckState(QtCore.Qt.CheckState.Unchecked if fixed else QtCore.Qt.CheckState.Checked)
+        if fixed is not None:
+            self.fixed_check.setCheckState(QtCore.Qt.CheckState.Unchecked if fixed else QtCore.Qt.CheckState.Checked)
 
-        self.global_checkbox.setCheckState(QtCore.Qt.CheckState.Checked if glob else QtCore.Qt.CheckState.Unchecked)
+        if glob is not None:
+            self.global_checkbox.setCheckState(QtCore.Qt.CheckState.Checked if glob else QtCore.Qt.CheckState.Unchecked)
 
     def get_parameter(self):
         try: