I have followed the sample of Microsoft regarding create SPFx Extension. Everything worked well until I deploy it to the site.
After deployed the app into App Catalog, I could see the feature is activated on the destination site but there is no top/bottom placeholder show up in the modern UI.
I checked the console but found no issue as well:
The weird thing is if I debug using the browser (Chrome) I can see that the break point at variable declaration is hit (const LOG_SOURCE) but the override onInit function is not hit.
Thanks,