Upload changed files with external changes automatically doesn't work after PHPStorm update

After updating PHPStorm from 2020.2.4 to a newer version (currently 2021.2.2), the automatic file upload of external changes is not working anymore.

I have the following settings in Deployment > Options: 

- Upload changed files automatically to the default server: Always
- Skip external changes: unchecked

I am creating css and js files with a gulp task. The gulp task runs correctly, but the generated css and js files are not recognized by PHPStorm. Only when I click on "Reload All from Disk (Strg+Alt+Y)" or when I open another window, switch tabs etc., the IDE realizes the new files and uploads them.

This used to work before and it works for my colleagues with the same settings. The PHPStorm update has broken the feature for me.

Is there any way to fix this?

Thanks and best regards,
Thomas