I can't disable fully qualified field names. In the ModelBuilder I have unchecked "Maintain fully qualified field names" in the Environments. I've also made sure it's unchecked in each of the tool environments. When I first build my models this was not an issue, then they just started appearing fully qualified.
My models run several variations of data through the Optimized Hot Spot Analysis and Kernel Density tools.
Is there a chance that input fields from different datasets are causing this? or are you using the same input data with just variations of some of the parameters?
I use a singe dataset imported from a .xlsx file. So I don't even have any joins. The extra names all come from within the model.
So it isn't even a geodatabase table then? I can see no reason why a model would revert and environment parameter if a run completely terminates before restarting
There is a Python snippet that will disable fully qualified names -
arcpy.env.qualifiedFieldNames = False
Not sure how you could add this to your model though.