diff -ru source.bak/data/backend_helper.py source/data/backend_helper.py
--- source.bak/data/backend_helper.py	2023-04-30 21:20:07.986410268 -0400
+++ source/data/backend_helper.py	2023-04-30 21:35:59.442841302 -0400
@@ -58,35 +58,14 @@
         return _install_all_updates_synaptic()
 
 
-# check updates
-def _check_updates_aptdaemon():
-    from gi.repository import Gtk
-    from aptdaemon import client, enums
-    from aptdaemon.gtk3widgets import AptProgressDialog
-    client = client.AptClient()
-    trans = client.update_cache()
-    dia = AptProgressDialog(trans)
-    dia.connect("finished", Gtk.main_quit)
-    dia.run()
-    Gtk.main()
-    return trans.exit == enums.EXIT_SUCCESS
-
-
-def _check_updates_gtk():
-    cmd = ["/usr/bin/synaptic-pkexec",
-           "--update-at-startup",
-           "--non-interactive",
-           "--hide-main-window",
-           ]
-    subprocess.call(cmd)
-
-
 def check_updates():
-    """ check for updates either with aptdaemon or synaptic """
-    if HAVE_APTDAEMON:
-        return _check_updates_aptdaemon()
+    """ check and show updates using update-manager """
+    if os.path.exists("/usr/bin/update-manager"):
+        cmd = ["update-manager", "--no-check-screen"]
+        res = subprocess.call(cmd)
+        return (res == 0)
     else:
-        return _check_updates_gtk()
+        logging.error("update-manager is not installed")
 
 
 # start packagemanager
diff -ru source.orig/data/backend_helper.py source/data/backend_helper.py
--- source.orig/data/backend_helper.py	2023-05-01 10:18:12.941023681 -0400
+++ source/data/backend_helper.py	2023-05-01 10:27:12.724396819 -0400
@@ -53,9 +53,10 @@
 def install_all_updates():
     """ install all updates either with synaptic or aptdaemon """
     if HAVE_APTDAEMON:
-        return _install_all_updates_aptdaemon()
+        _install_all_updates_aptdaemon()
     else:
-        return _install_all_updates_synaptic()
+        _install_all_updates_synaptic()
+    return show_updates()
 
 
 def check_updates():