Breaking change in recent dockerhub update?

Guys, is anyone else having issues with DockerHub automated builds? I cannot get anyone to acknowledge my issue since the recent upgrade to docker 17.06.1
I have an automated build which is triggered with an API call that specifies the TAG value. However, it looks like it is treating the tag as a branch which is failing because it does not exist.

Example API call:

curl -H "Content-Type: application/json" --data '{"source_type": "Tag", "source_name": "0.3.0"}' -X POST https://registry.hub.docker.com/u/<repo>/<docker-image>/<Token>/

Error:

Building in Docker Cloud's infrastructure...
Cloning into '.'...

warning: Could not find remote branch 0.3.0 to clone.

fatal: Remote branch 0.3.0 not found in upstream origin

Unexpected end of command stream

please ensure the remote branch exists (128)

Some of my failing builds:
https://hub.docker.com/r/theyorkshiredev/trigger-dockerhub-build/builds/