How can I navigate to the .java file declaration of another module in Android Studio?

Question

I'm working on a legacy Android project in my company, and until recently we were using Gradle 2.14.1. We're now using 4.10.2, but since upgrading, and probably due to the incremental build feature, when I navigate to the declaration of a class/method declared in a different module, instead of opening the .java file, Android Studio opens the .class file, which is quite inconvenient if I need to edit it.

Also, on a probably related note, classes and methods declared on a different module don't show any usages, and are marked as unused, even though their .class counterparts are shown as used.

Is there any way to configure Android Studio, or my project, so that the references will once again link .java files instead of .class files?