MicMack

Hello, I have a 2010 F150 5.4L V8 Platinum recently purchased with 115,000 miles. I just noticed an issue while I'm on the highway, usually above 55 and less than 75 miles an hour. Cruising up to that speed and at that speed is fine, but if I press the gas down and shift all the way down into third gear to pass someone, you can notice a tiny amount of shaking, hesitancy and stuttering with the transmission. The transmission light comes on and blinks after driving normally for about a minute and then turns off and all is fine. Today however the was first day the light remained on all morning. If I have the music off and the windows down, I can hear the exhaust sounding airy, not how a healthy V8 roar and hum sounds. Almost sounds like forcing air through something that has a hole in it. This is the only circumstance where I've experienced this and can replicate it, never at lower speeds even or flooring it from 1st to 2nd or second or third. Any ideas as to what this can be and the kind of fix that might be required? Or if it even needs to be fixed? I can avoid this altogether by not flooring it at those speeds and just downshifting to fourth. Thanks