At work we have no direct connection to the internet.
To fetch maven artifacts we need to use a local Nexus, which mirrors all of maven-central.
I have a settings.xml containing the needed configuration. (Hostname, password, etc.)
Running mvn from the command line works fine. (Both for fetching regular jars and sources.)
Intellij however is not able to fetch any artifacts. Looks like it uses the correct server, but maybe(?) does not authenticate.
I cannot see a helpful error message in intellij. However in my .m2/repository instead of the artifact I find a file *.jar.lastUpdated which says:
.../public-snapshots/.error=Could not transfer artifact ... from nexus (*Correct URL*):
Transfer failed for https://*correct URL*.jar
So it look like Intellij tried to fetch the file from the correct server, but was not able to do so.
Any idea what might be the problem here, or where I could find a more detailed error message?
(In the maven options of Intellij I already set the correct MAVEN_HOME and the correct settings.xml. According to the above message Intellij also read the settings file to replace the correct URL.)
Here is the requested settings dialog:

Also running Maven explicitly using the lifecycle targets in Intellij works fine, but any internal features like "Download sources and documentation" fail.