Thanks so much!
I looked into converting the Premiere Pro mp4 to prores with ffmpeg, a free converter (forgot the name, has a cupcake watermark… VideoSolo?) and yours using a couple of settings, mainly to differentiate between HD and and lo-res to see if that helps. I also exported prores and DNxHD (bought the add-on) from Premiere.
I then used two computers to import and got almost identical results on both with all file types, basically the same behavior I put in the OP. The best performance I got on a free converter that at least creates a file that allows running the video in Cubase in sync after some manual offset adjustment.
I must be missing a bunch of steps, I’m sure Cubase isn’t this bad with video.
I wonder if there are best practices shared by the Cubase community somewhere… I found some handy ffmpeg switches, but nothing specifically related to working on Cubase Pro 11 and Premiere Pro. I’ll keep researching, but I’d be interested in hearing what kind of routines people have established for Cubase and working with video.