That is the way Tidal works. Without Exclusive Mode, Tidal only outputs 16/44. There is no reason for it to output 24/96 if the Windows mixer is going to take over and modify the signal. With exclusive mode set, Tidal is assured that the 24/96 signal gets to the DAC (or WDM in this case) unmodified. In addition, if Tidal is sending undecoded MQA directly to a DAC it needs to be sure that the signal is not modified by the mixer. That requires exclusive mode.
You can try it for yourself with WDM. Audio Path will tell you what the input sample rate is. Try Tidal with and without exclusive mode set. Or, if your DAC tells you the sample rate it is receiving, go direct from Tidal to the DAC with and without exclusive mode and see what the DAC is receiving.
EDIT: Let me correct this. Since the Windows Mixer takes over, you can not tell exactly what Tidal is putting out in non-exclusive mode. However, by most accounts, when in non-exclusive mode, Tidal does not output decoded MQA. But, I would need to find a definitive reference on that.
Remember, the main goal of MQA is to get the MQA signal to the MQA DAC, something that will not happen if the mixer modifies the signal.