Tx64 Request not returning Tx Status response

Sometimes I when send a Tx64 Request that asks for ACK that TxStatus is not returned. It especially happens when I send many Tx64 requests at once? Why is that?

First reduce the amount of frames you are sending. Next check the API frame to make sure that you provided everything you need for the status to be provided. Make sure that you are also providing a unique frame ID for each one.