<developer> entry stripped from poms in staging published by sbt-sonatype plugin

We are no longer able to release our sswf project because during staging our poms are somehow written with the <developer> entry stripped out. This causes the poms to fail the staging rules and the staging repository cannot be closed and so the release does not occur. I have verified that this happens even with sbt-sonatype plugin version 2.1.

We last deployed successfully 6 months ago. Deploying the exact same code now now fails with this error when the releaseAll command is issued:

[info] repositoryCloseFailed: id:combazaarvoice-1315, cause:com.sonatype.nexus.staging.StagingRulesFailedException: One or more rules have failed
[error] Failed to close the repository
[error] Activity close started:2018-03-01T01:52:25.278Z, stopped:2018-03-01T01:52:52.434Z
[error] Failed: pom-staging, failureMessage:Invalid POM: /com/bazaarvoice/sswf-example_2.10/5.0.1/sswf-example_2.10-5.0.1.pom: Developer information missing
java.lang.Exception: Failed to close the repository

We have not changed anything in our project since the last successful release. Can someone look into what might be causing the <developer> entry to be stripped from our poms?

If we publish locally everything is fine, this only happens when publishing to here. for reference, I have attached our pom file when published locally (+publishLocalSigned) and to Sonatype (+publishSigned).

The Bazaarvoice repo /com/bazaarvoice/sswf_2.12/6.3 was built successfully on 8/5/2017 and the same code can no longer be deployed because of the error described here. The new repos I was trying to deploy today (/com/bazaarvoice/sswf_2.10/5.0.1 and /com/bazaarvoice/sswf_2.11/5.0.1) also were impacted by this same error. 

It seems something has changed with the sonatype staging process since 8/5/2017 that is causing the sbt-sonatype plugin (both versions 2.0 and 2.1) to fail in this manner.