Fix distinct query for absences with custom excuse types

CHANGELOG.rst

@@ -11,9 +11,11 @@ Unreleased
 
 Fixed
 ~~~~~
+
 * In some cases, pages showing the count of extra marks and lessons with custom excuse types of
   persons threw an error.
 * The redirection to generated class register PDF printouts did not work.
+* Absences with custom excuse types were not counted correctly.
 
 `3.0b0`_ - 2022-02-28
 ---------------------

aleksis/apps/alsijil/model_extensions.py

@@ -482,7 +482,7 @@ def generate_person_list_with_class_register_statistics(
         persons = persons.annotate(
             **{
                 excuse_type.count_label: Count(
-                    "filtered_personal_notes__absent",
+                    "filtered_personal_notes",
                     filter=Q(
                         filtered_personal_notes__absent=True,
                         filtered_personal_notes__excuse_type=excuse_type,