Fb messenger issues between iphone user and android user

most likely not an apple issue, but just in case - Does anyone have any thoughts on why an android user would receive a notice that the recipient is unavailable when trying to send a message on messenger to an iphone user? History: fb was deactivated, keeping messenger. Iphone users still able to send messages through messenger. Android users unable to. Reactivated fb to see if that would solve the issue. It did not. Google results state that the person they are trying to message has blocked them or deleted their account. Neither is the case.

Not sure there is anything the iphone user can do, but exploring all possibilities