Chosen dark background color disappears when print to pdf - to regular white


I am having some trouble with saving a file as a PDF, where the background color does not show and comes in white instead. The viewport layout shows the correct dark background color, but when I chose to Print to PDF the document background is in white.

In the Print Setup box, I checked and unchecked both and separately Background Color and Background Bitmap, to which the preview box shows the correct color. Trying to check and uncheck those boxes does not show the correct color when the pdf is opened.

When the Print Setup Destination is <Image File (PNG, …)> the file is saved with the correct color, with very low definition. The problem issue persists if I save it as PDF.

Thanks for your time!!