Could you share a sample file so we can see the volume of paths you are creating and possibly I can test zooming on my machine to see if it compares?
I've sent my file to your email link just because I can't show it on a public forum yet, so your discretion would be appreciated.
Hi Gary, it hasn't come across yet.
[Private information removed by moderator]
I've found out a bit more about this Mark.
It seems dragging the image window over to my non-Retina 24" 1920 x 1200 second screen solves it, the scrubby zoom is smooth. It's looking like the Retina 27" iMac screen at 5120 x 2880 is struggling to redraw the pathing in real time even with 4GB onboard the Radeon Pro 570.
I guess there must be so much info in rendering the paths in CC19 compared to last years previous version. I really thought turning off 'Anti-alias Guides and Paths' might solve a problem like this but it'll take someone with a better specced iMac GPU to prove a fast card redraw overcomes this.