In my case, this is sway, verified by the wife in a car behind me and able to be felt in the ride of the truck. The back end of the trailer is oscillating back and forth and coming close to or just over the lane line. The SwayPro does seem to be handling it, and manually activating the trailer brakes does as well, but I’m concerned that it has suddenly appeared.
So is the consensus that new, otherwise suitable tires can cause minor sway to occur until they are broken in? If so, I’ll simply try to put as many miles on the tires as I can before we leave for vacation in a week. If not - what else can I do?