Recently you changed the copy to checkout link.
For starters the whole Checkout in source tree thing is completely borked. No idea why it doesn't work anymore but it hasn't in over a year.

It opens a little window and then we try to check out existing but it just crashes SourceTree or takes us in loops.
It used to work fine but it's broken and we've wasted so much time trying to figure it out that we've given up on it completely. I'm on the latest version of SourceTree and it's still not working.
Anyhow... instead we've been copy and pasting the branch name as provided in the screenshot.
Recently for some mysterious reason the copy text no longer includes :
git fetch && git checkout <branch name here>
It only has the branch name. How do we tell Atlassian to put that text back? The support links and pages just takes us in circles without a good way to provide feedback for changes like this.