After enabled the annotation processor and installed lombok plugin, if still got "can't find symbol error" on lombok generated method, try check the gradle configuration, which is in
Preference -> Build,Execution, Deployment -> Gradle,
if you are using local gradle distribution, change to use default gradle wrapper.
I got this error when my project's gradle wrapper is 4.10.2 but my local gradle version is 5.1.1, and I solve it after I change it to use default gradle wrapper.