Issues with Contacts and Messaging
Some Businesses reported that message sending was failing (usually with a 1006 Unknown Contact error) even though the recipient contact was valid and a session (24 hour customer care window) was open.
This issue appears to be related to the recent WABA application upgrade to v2.39.1
We discovered that the contacts database was re-created during the upgrade resulting in a new database table for the ContactStore.
This is something we were not aware of as previous upgrades did not behave in this manner. META did not mentioned it in the upgrade notes or change logs.
As a workaround, we recommend checking contacts (/v1/contacts) before messaging.
Issues with Disconnecting Core-Apps
Some Businesses reported issues that relate to disconnecting WA Coreapps. A disconnected Coreapp can be identified by calling the v1/healthcheck endpoint which will return a disconnected status. Symptoms include an error response such as "Connection timed out. Please check if wacore is running" The reason for some Coreapps being disconnected is still not 100% clear at this stage. META Support have implementing enhancing logging on reported numbers to help identify the root cause.
However, it does appear to relate to Media handling - specifically how media URLs are uploaded to the Media volume. As a workaround, we suggest that you use media-ids to send media as opposed to media URLs.