The reason is this, (from the console):
pamac-manager
** Message: 08:57:49.105: flatpak_plugin.vala:393: refreshing flathub appstream data** (process:5499): WARNING **: 09:00:49.507: flatpak_plugin.vala:398: While pulling appstream2/x86_64 from remote flathub: While fetching https://dl.flathub.org/repo/delta-indexes/1g/rdmbJOYEewnufEmj+llieQH9y7cwYAbiNM3gsAyq8.index: [28] Timeout was reached
** Message: 09:00:51.335: flatpak_plugin.vala:393: refreshing flathub appstream data** (pamac-manager:5499): WARNING **: 09:03:51.713: flatpak_plugin.vala:398: Enquanto executava pull de appstream2/x86_64 a partir do remoto flathub: While fetching https://dl.flathub.org/repo/delta-indexes/1g/rdmbJOYEewnufEmj+llieQH9y7cwYAbiNM3gsAyq8.index: [28] Timeout was reached
(pamac-manager:5499): Gdk-CRITICAL **: 09:03:51.763: gdk_window_set_cursor: assertion ‘GDK_IS_WINDOW (window)’ failed
Is it my network? ( 404 Not Found )