Google Cloud Build Maven Artifacts upload failing with 'Broken pipe'

[brecht-y-tb]

We have a cloud build file that has uploads 4 rather large (75-100 Mb) Maven artifacts.

artifacts:
  mavenArtifacts:
    - repository: 'https://europe-maven.pkg.dev/our-project/releases'
      path: 'moduel/target/deploy/artifact-${_MVN_VERSION}.jar'
      artifact_id: 'artifact'
      group_id: 'io.trustbuilder'
      version: '${_MVN_VERSION}'

So far this has always worked well.

Since a few days we keep getting these messages

Uploading to remote-repository: https://europe-maven.pkg.dev/our-project/releases/io/trustbuilder/artifact/11-fff0dd1/artifact-11-fff0dd1.jar
Progress (1): 0/73 MB
Progress (1): 0.4/73 MB
                       
Uploading to remote-repository: https://europe-maven.pkg.dev/our-project//releases/io/trustbuilder/artifact/11-fff0dd1/artifact-11-fff0dd1.pom
Progress (1): 409 B
                   
Uploaded to remote-repository: https://europe-maven.pkg.dev/our-project/releases/io/trustbuilder/artifact/11-fff0dd1/artifact-11-fff0dd1.pom (409 B at 685 B/s)

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-deploy-plugin:2.8.2:deploy-file (default-cli) on project tb-suite: Failed to deploy artifacts: Could not transfer artifact io.trustbuilder:artifact:jar:11-fff0dd1 from/to remote-repository (https://europe-maven.pkg.dev/our-project/releases): Broken pipe -> [Help 1]

Previously we have gotten similar errors (Broken pipe) if the repository is in 'Release' mode and the artifact already exists, however now we even get these on an empty repository.

So far we have been tinkering with the permissions, but to no avail. How can we find out what the cause of the 'Broken pipe' error is without access to the actual Maven repository server?