6r80 shifting problems

Can someone help me figure out why my 2016 mustang gt 6r80 circle d 3200 3c won't shift at around 15% to 30% throttle? It shifts fine at really low throttle input and fine at sat 30 to 35 % or more throttle. If I'm in that 15 to 30% range it will go all the way to 4k rpms and just hang there for multiple seconds unless I let off the throttle then it will shift on its own. It will also shift fine using the paddles. I have worked with Scott hasty on tuning and none has changed the 15% to 30% shifting concern. Has anyone seen this before? I have checked tps and app voltages. Cleaned every ground. Checked the charging system. I figured out its in the tune somewhere. I flashed an older ngauge lund tune on the car and it shifts perfect.