The affixed header was not reappearing if page content was removed and the page thus indirectly scrolled. task-2446020 closes odoo/odoo#64999 X-original-commit: 4da6df09a4df195ad7c0caa7de7fbc7389339958 Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>