Correct graph data spikes

Hello!
I watched video tutorial “Correct graph data spikes”. It works , but there is a little problem. When I place the cursor on the desired position start % and stop % are always shows 0% and 2%. “WD” corrects this position and not the one we want.
If we manually enter an example start 25% ,stop 28%, “WD” corrects this position on the graphics


I had not tested that on the linux/mac version
probably needs some love