did you resurface the rotors?

if not , you need to start with that

I'll bet there's excessive run-out on one or possibly both rotors.
Sometimes it happens when the rotors are just slapped on the lathe.  The
bearing adapters used on the brake lathes aren't an exact fit (like the
tapered bearings used to mount the rotor to the spindle).  While the rotor
is on the lathe, even when it's locked down, if struck sharply or is hit by
a single cutting bit that's extended too far, will throw the rotor out of
alignment .  More that likely, the total run-out is exceeding the max limit.
The only way to check it is to use a dial indicator.