### Answer
I don't have specific documentation about SMS agent session handling, cache invalidation, or the behavior you're describing with inbound SMS agents in the available sources.
The issue you're experiencing—where a previous agent continues handling messages even after being removed or reassigned—appears to be a technical bug related to session management that isn't covered in the documentation I have access to.
For this type of platform-specific issue involving SMS agent session persistence and cache invalidation, I recommend:
*Visit [Documentation]() *
*Visit [Hire certified Retell partner]() *
Would you like a general answer based on my knowledge instead?