I am using REW for audio measurements using a Topping E50 DAC and a E1DA Cosmos ADC. I need to use WMD-KS backend as it appears that the other backends sometimes manipulate the data. However, when I select this backend, the sample rate selection drop-down becomes empty in REW. Any idea how to resolve this? If it helps, even using the other backends, sometimes the sample rate does not change on one or both products. I have also found that if I switch to another backend, change the sample rate, and then switch back to WMD-KS, it maintains the correct sample rate.