not sure what your program looks like, what motion instructions are used, what the motion parameters are, if the load is correct etc. also there is no indication of the magnitude of the oscillation, robot arm position when it is observed...
3000mm/min is only 50mm/sec which is quite low speed.
btw, few years ago i have seen some oscillations in cases where robot was near Alpha1 singularity (consoler robot mounted on an angle, and TCP was below robroot). so problem was sorted out by KUKA support after presenting trace and video of the issue. they provided instructions to manipulate value in MADA and disable elasticity compensation. after that thing was solid.
e. g.:Material type and depth of cutting, feed rate, spindle speed and diameter, distance between points
