Cannot ignore .idea/workspace.xml - keeps popping up

Using PHPStorm, I am trying to ignore the workspace.xml which pops up every-time I try to make a git commit.

My .gitignore looks like:

/.idea/
.idea/workspace.xml

Because at a point the file was committed, I've also executed:

git rm --cached .idea/workspace.xml and then committed the removal, pushed to a bare repo.

But the file keeps popping up later when I do changes in the project.

Any ideas on what I am missing?

I had to:

• remove the file from git
• push the commit to all remotes
• make sure all other committers updated from remote

Commands

git rm -f .idea/workspace.xml
git remote | xargs -L1 git push --all

Other committers should run

git pull