In fact going back and looking at the last week the peak temp recorded by this station is always in the period right before the shadow makes it down the wall to shade the module.
Looking back at the data this appears to have been this way for months. I just did not notice till the high temp alarms started triggering.
The downside of moving it to the north side is the WiFi signal dropped from 5 bars to 2 so I'll need to keep an eye on it to make sure it stays connected. (Actually Homeseer will do this for me.) I'm not too worried since the Wind sensor has been running fine at just 2 bars for awhile now.