Select in "Picture Settings" the following:
- Anamorphic: "Custom"
remove "Keep Aspect Ratio"
change PAR Width, PAR Height, Display Width
Then open a new file and select the previously saved preset.
It will show in Anamorphic: 0x0
You have to go to picture settings and place the cursor into PAR Width or PAR Height, then the Anamorphic is changing to the correct value.