off-road tyres will generate all sorts of road roar and tyre noise
its well worth trying a bit more tyre pressure to see if this alleviates the issue, just a few psi over the recommended maximum
and its also worth getting the suspension set up on a 4 wheel alignment jig
As most places use the back wheels as a datum and assume that they are perfectly straight and true. Often this is not the case and many modern cars are now adjustable at the rear as well as the front.A 4 wheel alignment measures all four wheels independently and each is set -up without referring to each other.
I'd agree its worth going back as it may be worth experimenting with a little less rear toe as this will help reduce tyre roar