Pro Tools 2020 Virtual Instrument/Midi Timing

[Howardk]

Having a lot of issues with timing problems from Virtual instruments such as Stylus RMX and HALion6. Seems the audio timing ends up very different, depending on if the plugin is all just out of its main output, or if I spread it across multiple auxes (which I much prefer). I must admit I have not done a lot of MIDI in Pro Tools over the years, but really prefer it because of access to my HDX cards and it is the audio environment I know best. Any magic tricks to getting Pro Tools to play nice in this area?

I am on a Mac Pro Ultimate 2012 12 Core 3.46Ghz on Mojave Pro Tools 2020.5, EB7 Chassis with 2 HDX cards. It is a pretty stable system for the most part, and I have buffers at 1024. This problem is much less pronounced with Automatic Delay Compensation Off, but still feels out. . . and there are other reasons i would like ADC engaged.

I have not worked on this exhaustively yet, but hoping some early insight may help be get this worked out quickly. . . or do I have to switch to Logic or Cubase Pro for this project?