Teams Chat Retention Policy not working as intended

[RMDUser1]

I wonder if someone can advise why my Teams Chat Retention policy hasn't deleted all the messages expected please?

The policy is brand new (and the only one we have) and only for a small group of users.

It has been 7 days since it was implemented.

The status of the policy is showing as Enabled (Success).

1-2-1 chats - most of these have been deleted.

Groups chats - some have been, some have not.

Meeting chats - none have been deleted.

As far as I'm aware, no other retention policies contradict this one.  There are no holds in eDiscovery and no ligation holds.

[#2]

Hi,
If I ready your question correctly you state that only a small group of users have retention policies configured.

In the chats that are not deleted, are there participants that do not have the policy applied?

/Patrik

[#3]

Hi yes only a few users for now to test the policy (it will eventually apply to the entire tenant).

So one user is present in some of the group chats and meeting chats. But they are also present in one meeting chat that I found has been deleted.   Some of these chats also contain users who are not longer employed (so show as Unknown User).

Is it potentially just very slow in picking up and deleting relevant messages? Is there a longer lag (than the 7 days) when a policy is first implemented? We would have years worth of messages to clear. Or is there a limit in how many messages are deleted per run??