Hi Matthias,
Based on the documents you shared, I found the grid settings in the "doesn't work" document is not the default value.
Given this situation, I suggest you follow the steps below to add the Grid Settings button to the QAT bar so that you can configure this:
- Go to Word and click the arrow on the Quick Access Tool bar as below:
- Select All commands in the Choose commands from selected box.
- Find Grid Settings and click Add > OK.
- Click Grid Settings and change the setting as the following:
- Go to View and check Gridlines.
Hope this can resolve it.
Regards,
William