Meta have advised that the fix for disruptions impacting message sending, caused by coreapps being stuck on the WhatsApp On-Premise API, has been deployed. This issue has now been mitigated as of 11 August, 6:06 AM PST on the new version 2.49.3. Affected numbers will be upgraded to 2.49.3 in due course.
See Meta's Status page for more information and updates.