Make sure your Variable Hihat module mapping is correct: Default setting without any e-drum preset (what I highly recommend in order to be able to reach all available EZX kit piece articulations with a dedicated note number):  set both BOW ( = Tip / “Head” articulation) note numbers (OPEN and CLOSED) to note number 20 and set both EDGE ( = “Rim” articulation) note numbers (OPEN and CLOSED) to note number 18. The Pedal note is note number 44.

You might also suffer from internal crosstalk on foot stepping when using a VH-10 system (as there is no “Noise Cancel” hihat module setting in TD-17): that means that due to the vibrations from the stepping unwanted BOW notes are generated. There is only one option to get rid of these unwanted BOW notes on modules like TD-17 (especially if you want to maintain the option to be able to play soft hihat hits and therfore wouldn’t want to make any extreme threshold settings): I provide a special fix that suppresses the unwante BOW notes (it’s based on a midi engine that suppresses the note within a certain time range (of a some milliseconds) after a pedal note comes in.)

I recommend a separated hihat controller system with FD-9 in order to get rid of VH-10/11 shortcomings (these things kinda fail by construction: also, the wanted openness can be corrupted by (hard) strokes due to the jolt downwards because the “motion unit” is kind of directly connected to the pad).

And then there is the EZ Drummer (also SuperiorDrummer) hihat engine behavior: [transition artifacts + ringing on fast stepping] which can be fixed for Roland modules: EZ Drummer 2 – Hihat Engine FIX  . Here is a video showing the issue + the fix.