Lane automation issue

In Pro 8.0.20 when I make adjustments to lane automation while playing audio, the Cubase pro timeline will freeze for 5 to 10 seconds but the music keeps playing. There is no spike in the CPU meter while it freezes. This does not happen in 7.5 running on the same high end machine.

I have disabled all 3rd party plugins to rule them out. I swapped my video card from GFX to AMD but same issue.