Bitrise project dependencies caching

Hello bitrise team,
Currently I’m checking the app size in each branch running specific workflow for certain commits in Pull request. I’ve noticed the strange behaviour in some PR app size checks.

Let’s assume we in the one of the commit in development, and there was a project dependency lib v3.1, and the app size was 60mb. And in this point the new branch was created, so in the commits of this branch the lib version and size were the same as development. Later some other commits were pushed to development, and in the one of commits the lib version was updated to v3.2 and app size decreased by 3mb and became 57mb and in the branch which is neither rebased or merged with development(doesn’t know anything about development) the app size was decreased too with exact number - 3mb, but the lib version was v3.1.

Here is a question: is it somehow possible that development build dependencies cache was used in the branch build? maybe here some hidden optimisation. Could you help me with this?

Thank you in advance