Perhaps you are encountering I/O (instant-on) radar which is accounting for the close detection ranges...if radar isn't actually being transmitted, then your detector won't alert.
Perhaps a way to "test" your system is to approach known stationery X, K, or Ka sources which can come in the form of radar drones/speed signs along the roadway and/or door openers which operate on X or K-band.
Also if your 9500ix is set to Auto Sensitivity mode (as opposed to Higway mode) the detector's response to X and K will significantly decrease at lower speeds. Perhaps try Highway mode (if you are not already).
Finally, make sure your band selection is correct in the programming setup.
Otherwise you may want to PM the Escort Rep who visits this forum for further guidance.