Custom ICC profiles in Capture One 12

I have been trying to find information about how to create and use custom camera profiles in Capture One 12. I have located some videos and articles online but they don't answer my question which is:
I have created several profiles for my Fuji X-T3 and X-H1 using Lumariver and followed their instructions but I come up short. It appears from videos online that they load their ICC profile in the ICC Profile drop-down menu and then load the Auto curve in the Curve drop-down menu and the output changes depending on what ICC profile they load. In my case, if I do the same, nothing changes when I use the Auto curve. I have to use the Linear response curve to discern any difference in output. Is this the way the software is intended to behave or am I doing something wrong?
It's perplexing and annoying since I have been using X-Rite profiles together with Lightroom for many years and I was expecting the same simplicity when working in Capture One 12. My intention was to migrate from Lightroom to CO 12 but before this issue is solved, I won't be able to. Your assistance would be much appreciated.