Hello,
Could you please, downgrade your php version on the site from 7.4.33 -> 7.4.1 or 7.4 and check then ? We’ve found next error log inside error_log file -> https://prnt.sc/7MgvUByNQSkw There is similar issue raised here -> https://wordpress.org/support/topic/cron-reschedule-event-error-for-hook-jetpack_sync_cron/
As an idea about looking for the hole of the issue was to downgrade Elementor plugin on your web-site also. We did it but with no success. Once you downgrade your php version, please, give us feedback here.
Regards
