Try rebalance and road test them. You might have lost a weight
or the tire guy might have put the weights on wrong.-Bob
Get the tire pressures even, side to side.

I have found other problems by:
I have found problems on a particular side, by making slow
circles in an empty parking lot, and listening/feeling through the wheel.
Then going slowly in the opposite direction. It will sound/feel differently, if one tire has problems.

and some times for no reason whatsoever, a brake disc warps, and will produce a shake as a person is braking hard. Weigh the replacement cost of two discs, versus having BOTH discs "cleaned up". It doesn't need a lot taken off, unless the parts guy is trying to sell new discs to you.

Keep us posted as to what you find.-Bob