:jshell task :classes not found, be sure to compile the project first

Even when running
```
./gradlew --console plain classes jshell
```
I still get the message
```
:jshell task :classes not found, be sure to compile the project first
```

I haven't been able to figure out what could be causing this. Could you point me in the right direction?

I'm using Java 13.0.1 and Gradle 6.5 on macOS Catalina (10.15.4).