I had same issue with my 12v Escort radar plug that didn't work in front 12v socket...but it did work in the 12v socket in the rear cargo area. (Have you tried your cargo socket?)
To verify my front socket works I plugged in my 12v to 110v AC converter...and it worked in both front and cargo 12v sockets. Both plugs appear to be same lenghs, but Paladin1 is right in that I tried the Escort plug in a BMW 228 front 12v socket and it didn't work there either. But it does in my 2010 BMW 650 front socket. My BMW service tech had no clue why the iX front socket didn't like the escort plug.
I decided to install a mirror wire (hardwire) power cord for my Escort to one of the 12v connectors behind the mirror. Great setup not having any dangling cords from the detector to the control console. There's a YouTube video on how to access that connector...the video is for an i4, but the iX access isn't much different.
Here's what I used: https://www.amazon.com/Radar-Mount-...663439996&sprefix=Mirror+wire+,aps,133&sr=8-4