and this is the output of sudo gnome-software :

(gnome-software:6185): Gs-WARNING **: Failed to create permission org.freedesktop.packagekit.trigger-offline-update: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: Action org.freedesktop.packagekit.trigger-offline-update is not registered

(gnome-software:6185): Gs-WARNING **: Failed to create permission org.freedesktop.packagekit.trigger-offline-update: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: Action org.freedesktop.packagekit.trigger-offline-update is not registered

(gnome-software:6185): Gs-WARNING **: Failed to create permission org.freedesktop.packagekit.trigger-offline-update: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: Action org.freedesktop.packagekit.trigger-offline-update is not registered

(gnome-software:6185): Gs-WARNING **: Failed to create permission org.freedesktop.packagekit.trigger-offline-update: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: Action org.freedesktop.packagekit.trigger-offline-update is not registered

(gnome-software:6185): Gs-WARNING **: Failed to create permission org.freedesktop.packagekit.trigger-offline-update: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: Action org.freedesktop.packagekit.trigger-offline-update is not registered

(gnome-software:6185): Gs-WARNING **: failed to call gs_plugin_add_category_apps on appstream: Failed to parse /usr/share/app-info/xmls/org.freedesktop.fwupd.xml file: cannot process file of type application/x-go+xml

(gnome-software:6185): Gs-WARNING **: failed to call gs_plugin_refine on appstream: Failed to parse /usr/share/app-info/xmls/org.freedesktop.fwupd.xml file: cannot process file of type application/x-go+xml

(gnome-software:6185): Gs-WARNING **: failed to call gs_plugin_add_categories on appstream: Failed to parse /usr/share/app-info/xmls/org.freedesktop.fwupd.xml file: cannot process file of type application/x-go+xml

(gnome-software:6185): Gs-WARNING **: failed to call gs_plugin_refine on appstream: Failed to parse /usr/share/app-info/xmls/org.freedesktop.fwupd.xml file: cannot process file of type application/x-go+xml

(gnome-software:6185): Gs-WARNING **: failed to call gs_plugin_refine on appstream: Failed to parse /usr/share/app-info/xmls/org.freedesktop.fwupd.xml file: cannot process file of type application/x-go+xml

(gnome-software:6185): Gs-WARNING **: failed to get recommended applications: no get_category_apps results to show

(gnome-software:6185): Gs-WARNING **: failed to get popular apps: no popular apps to show

(gnome-software:6185): Gs-WARNING **: failed to get featured apps: no featured apps to show

(gnome-software:6185): Gs-WARNING **: Failed to create permission org.freedesktop.packagekit.trigger-offline-update: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: Action org.freedesktop.packagekit.trigger-offline-update is not registered

(gnome-software:6185): Gs-WARNING **: failed to call gs_plugin_add_distro_upgrades on appstream: Failed to parse /usr/share/app-info/xmls/org.freedesktop.fwupd.xml file: cannot process file of type application/x-go+xml

(gnome-software:6185): Gs-WARNING **: failed to call gs_plugin_refine on appstream: Failed to parse /usr/share/app-info/xmls/org.freedesktop.fwupd.xml file: cannot process file of type application/x-go+xml