Same here - Running Logic X 10.5.1 - also just updated Helix Native to the latest version. Helix Native is sluggish as hell. Any edits take forever, the meters respond VERY slowly. This sucks .. I really cannot get any work done with Helix performing like this.
Any Logic preference settings that might be of help? I have turned on Low latency Plug-Ins - no difference. My other plugs work just fine.
Thanks - Dennis