X52 Throttle wheel issue

My dad is using an X52 and we have both tried to assign trim to the throttle wheel axis but it only seems to work in an incredibly small zone either side of the “centre” so in effect it is working as a switch assigning full trim either way. I have tried tinkering with the sensitivity of the axis but nothing has worked so far. Anybody encountered this? More importantly, has anybody found a fix?

Thanks