Excel Analysis with Windchill

I made multiple parts using Excel Analysis in Creo and checked it into Windchill. (I'm using Windchill 10.2 MO30.) After I checkout the file from Windchill the link between Creo and Excel is broken and a new Excel with random name opens, any changes made to this Excel do not reflect in the part. I tried to edit the Excel Analysis hundreds of times, and once in a while (like 1 in 30) it so happens that correct Excel opens and changes made to this Excel do reflect in Creo. Why is this happens?