Hello,
yes, this is normal. The loco stops immediately when it reaches the stop contact. You can only change that using profiles. I don't know if there are profiles in the WDP 8.4 Version and I don't know if there are such in WDP 9. They sure are present in WDP 2009 and WDP 2009 and WDP 9 are often mistaken as the same version. But they are not!
In the new version WDP 2012 and 2015 you additionally have the iTDN - the intelligent Train Number Display. It allows you to do exactly what you want to do. You can stop your train at the beginning of the platform, in the middle, at the end, or at the signal. This is easy to use and profiles are not necessary for that (though they are still available).
There is no way to buy another version but the newest WDP 2015 from M Peterlin. I would recommend to change to the new version. Unfortunatelly your version is that old that you don't get an upgrade price anymore. The new version is multilingual and contains German, English, and Dutch.