Operating system: Windows 7
Graphics card: Geforce GTX 780ti
Date: 2018-11-129 15:57
perspective view re-enables after removing in preferences
Open Preferences>Interface and untick Auto Perspective.
Press 5 in the modeling viewport.
Save preferences again.
Save the file.
Re-open the file OR open a new file and observe that the viewport is back in perspective view.
In preferences the Auto Perspective checkbox remains unticked.