Yocto Linux Bluetooth Build Rescue

I have a project that can be built as either Ubuntu or Yocto.. its quite an extensive project with many files.
Recently I tried to added bluez a bluetooth library.. this works fine in the Ubuntu build.
On Yocto it complains about the missing bluetooth libraries..

I will attach the make file.. which shows that the compiler flags -I/usr/include/ (not sure required)
and linker flags.. -lbluetooth

In the sources the includes..
#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>
#include <bluetooth/hci_lib.h>
#include <bluetooth/sdp.h>
#include <bluetooth/sdp_lib.h>
#include <bluetooth/rfcomm.h>
#include <bluetooth/l2cap.h>

The bluez library is included at /usr/include/bluetooth

I include the makefile also for Yocto (TX6) and Ubuntu

Either you would need to login to my PC and solve it using AnyDesk.. or just tell me what is wrong.. I cannot provide the sources.