I've got the same issue on a near identical config both hardware and software. Main difference is my OS is 10.15.5 My plug ins run on a Soundgrid Server and it happens with or without SGS or without any plug ins or instruments. It can happen with six audio tracks from the PT100 surf jingle spot no plug ins no instruments. Still happens with the buffers set to max for a six track, 30 sec spot. So yeah, it's a problem. With Pro Tools. I can load the hell out of
any other DAW, playback, instruments, whatever and it will sing. It's a known issue that rears its head on some systems. Doing the tweaks and rebooting every time I launch PT has helped but it still pops up. This box is my personal box that's not used for production. It would be a deal breaker if it were.
On Mojave you can try to disable spindump and tailspind. Those are Darwin processes that are used to monitor and report on systems. They've been known to cause errors for CPU intensive apps. It may not solve it though some users say it helps.
Here's the Avid tech note
https://avid.secure.force.com/pkb/ar...3D1&popup=true
There's an updated syntax for launchctl that doesn't require the SIP to be disabled but the legacy syntax should still work in Mojave.