I can't get Downloaded Sources in IntelliJ working for composite builds, When having a normal Gradle project IntelliJ automatically downloads the sources of external dependencies, but in a composite build project this fails. It complains that the sources can not be downloaded. In the IDE I can click 'Choose Sources' and the sources are there in my user

.gradle

directory and selecting them does nothing. I tried looking in IntelliJ logging, but it doesn't generate any logging when this triggers. Is this a known issue? I reduced it to a minimal reproducer: https://youtrack.jetbrains.com/issue/IDEA-374157/Download-Sources-not-working-for-Composite-Builds

If the "Download..." thing does not work (like in your case), report it to JetBrains (as you did) and instead open the "Gradle" tool window and use the "Download Sources" button, this usually works and downloads all sources (and so it does in your MCVE).