Search conversations: Unsupported search modifier provided

Hi,

We’ve started receiving 400 Bad Request errors when calling the conversations/search endpoint. A request such as:

now returns:

We aren’t using any other modifiers, and there have been no changes on our side. The issue began on 23 July 2025. From what I can see, using after: is still documented and there’s nothing in the changelog that suggests this behaviour should have changed.

Do you have any insight into why this might be happening or whether anything has recently changed with this endpoint?