I followed this documentation https://learn.microsoft.com/en-us/purview/ediscovery-search-and-delete-teams-chat-messages to delete messages permanently.
I've created an eDiscovery case and collection using the premium feature and performed a search for a specific word across all mailboxes.
despite executing the purgeData API successfully, the target chat messages were still retained
there are no retention policy or holds configured. what can be the reason for this