I'm not familiar with that radio, but are you sure it's exactly the same as the other one.

I have changed it on other radios and some are just bent slightly different at the end so as to cause it to grab the notches a bit. Another on I saw had a slight dimple on the piece causing the same effect.

If in fact it is the same, chances are Hitec service can help you out with the correct one.

I fly everything with a smooth throttle. I started many years ago with helicopters and am so used to smooth, it feels awkward to me when it clicks.