Welcome aboard, Johnny. I'm new here as well. Those semis push a lot of air out of the way just moving down the freeway. Sounds pretty normal to me. Do a little dancing as you hit the wake turbulence a few car lengths back, get sucked in as the flow smoothes out along side then kicked out as you pass the bow shock. If that's the only time she wobbles, you're golden. That big fairing on the front might take some getting used to as well in that respect. I've had a few tank slappers in my time but they weren't caused by the tire per se - or a truck - but a mech fault like a bad bearing - wheels, triple tree, swing arm etc. Sounds like your bike's pretty tight, though. Those E3s aren't great tires but they're not bad. Give them a while at their right pressure and see what develops. Just mind those semis.