Eclipse Synchronized PHP Project: synchronize from remote to local only

Question

I have a debian server on which i develop a symfony4 application. I set the application up on the server.

Now i wanted to use eclipse PDT to work locally and upload changes back to the server when i save.

I did create the synchronized PHP project in eclipse. But somehow my remote's vendor folder got lost. So i went back to the remote and re-installed it using composer install. Et voila the vendor folder was back on the remote - the app working again. Now i wanted to download it to my local eclipse copy so i get the autocomplete/'intellisense' of eclipse PDT. That's why i went to right click on project->synchronized->synchronize active now.

But that just deleted my remote vendor folder. (Supposedly because it synced it away)

How to synchronize from remote to local only?

Kind Regards!