Incoming texts not showing on Bluetooth system

My i-phone 5s incoming messages are only randomly appearing via Bluetooth. Occasionally I receive one which displays in unread messages. When I move from unread to read it remains. Thereafter the text message disappears when I negotiate between unread/read. " No message using this filter " No historical record of any texts remain in the system Is there some incompatibility between Bluetooth and i-phone 5s set-up? My vehicle is a BMW F10. Thanks for help.