Hi Brett, a potential issue could have been using the Teamserver Push (Git) Trigger on an app still using SVN. However, I can see your on version 10.12 so that shouldn't be a problem. In your post you mention the pipeline doesn't trigger on a commit. Just to verify: are you commiting AND pushing to the teamserver? Just a commit isn't enough to trigger the pipeline.
If that isn't the issue: have you tried putting Just a wildcard (*) in the branch expression to see if it still doesn't trigger? That might help you narrow down the issue.