Strange result with high pass sharpen

[Big_Stan 18]

I am currently using Mojave, but the problem occurred with High Sierra also.  When I choose High Pass sharpen > CMD J > Adjust the Radius, I can see a slight halo at very low Radius levels (less than 1).  However, when I click Apply, the halo completely vanishes (the screen goes to a fairly uniform gray). The vanishing "halos" makes it difficult to estimate the best Radius setting to select.

I am using Capture One 12 and I set the Raw sharpening to zero and noise reduction to zero before selecting  "Edit in AP".

[anon2 1,592]

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[Big_Stan 18]

Thank you.  I'll give it shot.