Pull requests always are against master unless manually switched.

This is a very annoying bug. Here is what happens:

We have a master branch: "master".
I'm the UI Team Lead, so we have a feature branch: "UI/COOL-FEATURE"
I want to fix an issue in our cool feature, so I create a branch off the feature branch: "berry/REF-1234"

We have master->UI/COOL-FEATURE->berry/REF-1234.

I fix the issue: edit edit --> git add --> git commit --> git push

I go to make the pull request on the PR page: click on "Create Pull Request"
I get a pull request template with my recently-pushed commit and so on. This is add fine, but the PR is set up to merge into master, NOT into UI/COOL-FEATURE.

I can manually change this, and then everything looks OK, but it's annoying to have to do this. Can't your server know that branch "berry/REF-1234" was created off of "UI/COOL-FEATURE" and set up the PR properly?

Thanks for an otherwise pretty great product!