`cap run android` blank screen, "Cannot read property 'triggerEvent' of undefined"

When running the app through Capacitors live reload, the app does not work at all, not on emulators and not on real devices. The splash screen appears, but is never dismissed, and the inspector console has the error:
Cannot read property 'triggerEvent' of undefined.

I have tried adding android:usesCleartextTraffic="true" to AndroidManifest.xml, but no luck.

When building and running in Android Studio, the app works as normal.

Has anyone seen this before and know how to resolve it?