New Viewport Tool Overwrote Changes You Made to Layers Within a Work Area or Viewport – How to Get Your Layer Settings Back?
Issue
You made manual changes to layers within an existing viewport. You then used the Land F/X tool to& create a new Viewport, and the New Viewport tool wiped out your changes.
Cause
Our New Viewport tool is designed to make global changes to layers in your drawing. If you don't save your changes as a Layer State prior to creating a viewport, the New Viewport tool will overwrite all manual changes you've made to your layers.
Solution
First, try using the Undo command (or CTRL+Z) to reverse the creation of the viewport and revert to the manual layer changes you originally made. If you are able to Undo back to those layer settings, save them as a Layer State. Then create your viewport again and load your saved Layer State.
If you are unable to Undo out of the new viewport, you'll need to carry out your manual changes to the layers again.
Once you've made your changes to the layers, save them as a Layer State.
Create your new Viewport again, then load your Layer State to re-apply the manual changes you made to the layers.