Kinda odd seeing this thread because I have the EXACT same problem running Presonus Studio One with Hellx Native on macOS! It will run perfectly across multiple launches for about a day (i.e. 24 hours), then it crashes the DAW.
However, I DID run it up the flagpole with L6 support and their only suggestion was to completely reinstall the DAW... which made no sense, because all plugin versions (AU, VST) crashed every DAW and VST host I tried it with.
But I happened upon a solution: after installation, and you use the VST for the first time, it creates a set of folders in your user directory. There is a preferences file that you need to edit. On macOS, it's located here:
~/Library/Application Support/Line 6/Helix Native/Helix Native.prefs
In that file, there is a key called "Session Token" -- if you close the DAW, open that file, remove that key and value, and save the file... everything works again... for 24 hours.