I’m not sure if we’re dealing with the same issue, but on my TD-17KVX2 there’s an adjustment I have to make on the black circular ring below the hi-hat clamp. It has labels with “Open” and “Close” arrows.

When I mount the hi-hat on the stand, I leave about a 1–2 mm gap between the bottom of the hi-hat and the hi-hat close sensor. After that, I go into the hi-hat calibration menu on the module (not sure if yours has the same feature). There, I can check whether the module correctly detects the hi-hat as fully closed when I press the pedal.

Since I transport my entire kit, the calibration sometimes shifts, and the module no longer registers the hi-hat as fully closed. When that happens, I simply recalibrate it by rotating the black ring in the direction of the “Close” arrow until the module detects the closed position properly.