Thank you to all who contributed.
I read and tried each and every suggestion.
Eventually, I found the answer in a YouTube video. Just a passing glitch. I played it back and froze the image. There was my answer.
Last night I conducted my first ILS in the Cessna Longitude using WTG3000 mod.
The problem stemmed from my unfamiliarity with the G3000 system.
I was putting the localizer into the NAV1 correctly, but failed to transfer the frequency from standby to active.
Once that was accomplished I had a center green needle that was responding to the localizer.
On a side note, I did find the APP surprisingly unresponsive to the approach. Flew the approach with NAV.
NAV would lock onto the localizer, but select APP and the plane wandered off course.
Glide slope and NAV did the trick for me.