How to get all 27 bytes of payload in BlueNRG.

[PDavi]

I have a custom primary service (in server role) with a R/W characteristic set for 27 bytes of data and GATT_NOTIFY_WRITE_REQ event mask. My android client app is sending a verified 27 byte payload to this characteristic. I only get events with 20 byte data length and only the first 20 bytes of the payload in the data buffer. hci_read_buffer_size returns 27 bytes as the packet length. HOW do I obtain the full 27 byte payload??