Hi
Each DWM1000 is tested for various parameters such as current, TX RF power, RX sensitivity. They are also calibrated for crystal trim and the trim value is stored in the on-board OTP memory.
When using a DW1000 (instead) one needs to calibrate the design (pw, Crystal, Antenna delay) . Have you checked the antenna delay and TX power of the DW design (Delay might be zero, while power high)
As a starting point for antenna delay maybe use what is applied to your DWM design.
See IC user manual for details
/leo