In your local repo directory, you should use git fetch -p (or git fetch --prune) command. Then you will find the deleted branches from remote won’t showed in remotes/origin in VS Branches panel.
This is because git fetch won’t check the tracking references exist or not from remote repo. But for git fetch -p, it will check if the tracking references exist or not and delete non-existing ones before fetching.
Reference Link – https://stackoverflow.com/questions/45191234/how-can-i-refresh-the-list-of-remote-branches-in-my-visual-studio-2017-team-expl
