I've 'heard' that new tires often take about 1000 miles to "break in"??? Now, that's just "internet" ramble, but I can kinda relate because when I've gotten a new set of tires on my old truck, they seemed a bit more squirmy until they had some miles on them..
I went thru 3 sets of new tires on the same truck, towing the same trailer for over 11 years and right after getting a new set, it didn't seem right for the first couple of tows?? But after awhile, I didn't notice??
Just a thought??
Mitch