Panadapter #1 problem?

Flex 6700 Radio While Running 2 Panadapters on 20 meters today I noticed that the first Pan had a slowly rising slope on the higher frequency end of the scale. So I set both pans up to be identical (frequency, vertical and horizontal scale, Averaging, FPS, bandwidth, etc.). The result was a definite 5 db slope across Panadapter #1. To double check on which one was right, I set all 8 Panadapters to be identical. The other 6 pans agreed with pan 2 very well as shown in the attached photo. Where the 7 pans showed the noise floor to start and end at approximately -115 db, pan 1 started at -115 db but then sloped up to end at approximately -110. Since the picture is small compared to the 43-inch monitor (TV) it is hard to make out all the details, but the difference can be seen between the end of pan 1 (upper left) and start of pan 5 (upper right). I wonder if anyone else has this problem (if it is a problem) or should I submit it to the Flex tech guys for investigation. Al, N4AB