I was very frustrated with this too, but I found a fix. Go to Edit>Preferences>Categories:>Page Display>Default Layout and Zoom, and then set "Page Layout" to "Single Page" and also set "Zoom" to "Fit Page" it should make "Fit One Full Page" the default when you open a PDF.
I was very frustrated with this too, but I found a fix. Go to Edit>Preferences>Categories:>Page Display>Default Layout and Zoom, and then set "Page Layout" to "Single Page" and also set "Zoom" to "Fit Page" it should make "Fit One Full Page" the default when you open a PDF.