Clone the example Plasmic project (Plasmic), publish it and run locally with headless API (preview: false).
Substituted components are not rendered. No error present.
With “preview: true” everything is working fine.
If you don’t use <PlasmicComponent> wrapper but build your own in-code React component with returning the jsx code, it will substitute a plasmic component completely and will be rendered.
Thank you for reporting this bug! It was introduced on version 1.0.360 of @plasmicapp/loader-nextjs and should be fixed by upgrading it to version 1.0.363 or later.