I encounter this problem many times a day while using SourceTree. When I switch focus to a SourceTree git repository window and click on a branch (e.g. develop), it clears the history and then some time later it shows it. Sometimes this only happens after switching to a different view and then switching back.
For background, the git repository has two remotes, one hosted on a Mac server on our LAN specified using an IP address, and one on GitHub. I have probably 30 or 40 total repositories listed in the Bookmarks window.
This has become more and more of an annoyance, making SourceTree - one of my favorite tools, by the way - less and less useful, even painful to use.
Let me know if there is anything you'd like me to provide to you to troubleshoot this problem.
Thanks,
David