Syncing columns from Project to SharePoint

I set up a project with several operations in MS Project.

Meanwhile I also discovered how to set up tasks in SharePoint with the appropiate app.

Now SharePoint offered me to open the task with MS Project vice versa.

But now the problem starts. User defined columns I inserted via SharePoint don't show up in MS Project. And neither do in SharePoint that I inserted in MS Project. That's kind of anoying.

Does anybody have a workaround how to solve this?

Thanks in advance!

Lutz