Is yours the 2020 or 2019 model?Would you please let us know how Mizuno responds? My daughter has a new PC 32/23 and has been complaining about vibration as well ... on balls that look to be squared up and hit hard. I just assumed the feel of the bat was “different” than her older xeno and that maybe it would take a little while for her to adjust (bat does seem to be at least as hot as her xeno, so no obvious issues there). I didn’t think about trying it myself using the “dad fungo” method, but I’ll do that today ...
I can imagine Mizuno having a factory/build quality issue that affects a small percentage of bats off the line ... anything mass produced will result in units that aren’t “optimal” in terms of performance. I just hope if the vibration you are experiencing is a known issue, Mizuno will address it for the benefit of affected customers.