diff --git a/gramps/plugins/textreport/detancestralreport.py b/gramps/plugins/textreport/detancestralreport.py
index 6af22cb20..adb8e1f20 100644
--- a/gramps/plugins/textreport/detancestralreport.py
+++ b/gramps/plugins/textreport/detancestralreport.py
@@ -484,7 +484,7 @@ class DetAncestorReport(Report):
 
         if self.inc_attrs:
             text = ""
-            attr_list = event.get_attribute_list()
+            attr_list = event.get_attribute_list()[:]  # we don't want to modify cached original
             attr_list.extend(event_ref.get_attribute_list())
             for attr in attr_list:
                 if text:
@@ -504,7 +504,7 @@ class DetAncestorReport(Report):
         if self.includenotes:
             # if the event or event reference has a note attached to it,
             # get the text and format it correctly
-            notelist = event.get_note_list()
+            notelist = event.get_note_list()[:]  # we don't want to modify cached original
             notelist.extend(event_ref.get_note_list())
             for notehandle in notelist:
                 note = self._db.get_note_from_handle(notehandle)
diff --git a/gramps/plugins/textreport/detdescendantreport.py b/gramps/plugins/textreport/detdescendantreport.py
index 0cb0e1a38..ac36a488a 100644
--- a/gramps/plugins/textreport/detdescendantreport.py
+++ b/gramps/plugins/textreport/detdescendantreport.py
@@ -509,7 +509,7 @@ class DetDescendantReport(Report):
 
         if self.inc_attrs:
             text = ""
-            attr_list = event.get_attribute_list()
+            attr_list = event.get_attribute_list()[:]  # we don't want to modify cached original
             attr_list.extend(event_ref.get_attribute_list())
             for attr in attr_list:
                 if text:
@@ -529,7 +529,7 @@ class DetDescendantReport(Report):
         if self.inc_notes:
             # if the event or event reference has a note attached to it,
             # get the text and format it correctly
-            notelist = event.get_note_list()
+            notelist = event.get_note_list()[:]  # we don't want to modify cached original
             notelist.extend(event_ref.get_note_list())
             for notehandle in notelist:
                 note = self._db.get_note_from_handle(notehandle)
diff --git a/gramps/plugins/textreport/indivcomplete.py b/gramps/plugins/textreport/indivcomplete.py
index 13c169955..30483f37d 100644
--- a/gramps/plugins/textreport/indivcomplete.py
+++ b/gramps/plugins/textreport/indivcomplete.py
@@ -256,7 +256,7 @@ class IndivCompleteReport(Report):
 
     def write_note(self):
         """ write a note """
-        notelist = self.person.get_note_list()
+        notelist = self.person.get_note_list()[:]  # we don't want to modify cached original
         notelist += self.family_notes_list
         if self.names_notes_list:
             for note_handle in self.names_notes_list:
diff --git a/gramps/plugins/webreport/basepage.py b/gramps/plugins/webreport/basepage.py
index 1236ca4ad..bb22dcf7e 100644
--- a/gramps/plugins/webreport/basepage.py
+++ b/gramps/plugins/webreport/basepage.py
@@ -679,13 +679,13 @@ class BasePage: # pylint: disable=C1001
         trow += Html("td", srcrefs, class_="ColumnSources", rowspan=2)
 
         # get event notes
-        notelist = event.get_note_list()
+        notelist = event.get_note_list()[:]  # we don't want to modify cached original
         notelist.extend(event_ref.get_note_list())
         htmllist = self.dump_notes(notelist)
 
         # if the event or event reference has an attribute attached to it,
         # get the text and format it correctly?
-        attrlist = event.get_attribute_list()
+        attrlist = event.get_attribute_list()[:]  # we don't want to modify cached original
         attrlist.extend(event_ref.get_attribute_list())
         for attr in attrlist:
             htmllist.extend(Html("p",