how to delete a singel fixture override fadetime in a cue?

we try for hours, an now nearly for days to remove a singel fixture overide fadetime in a cue with several override fadetimes.
if we select the override cell and press “-”, enter, there is no problem to delete all overridetimes from this cue.
BUT if we try to do the very complicate steps from manual to delete for example fixture 12 overridetime and leave all others, it will not work at all with our possibillitys.

please, can anybody guide us thruh this crazy horrible way to edit a simple thing like this in a cue?!?



-Hit Edit cue X (with the cuelist selected)
-Select your fixtures,
-Hit clear, in the clear windows select only the Time and your parameter,
-Hit enter
-Press update