Desktop & Screen Saver images gone again

Thanks for posting in the Apple Support Communities Kayeffcie,

The following steps can be used to set a wallpaper on your Mac:

1: On your Mac, choose Apple menu  > System Settings, then click Wallpaper  in the sidebar. (You may need to scroll down.)

2: Select a desktop picture from one of the available categories:

* Dynamic Desktop: These pictures change gradually throughout the course of the day based on your current location. If Location Services is turned off (in Privacy & Security settings), the picture changes based on the time zone specified in Date & Time settings. See Change Privacy & Security settings.

* If you selected Dark Mode in Appearance settings (or during macOS setup), the desktop picture defaults to a dark still image. To stop using a dark still image, click the pop-up menu, then choose Dynamic or Light (Still).

* Light & Dark Desktop: These pictures switch from light to dark at sunset, based on your current location. However, if you selected Dark Mode in Appearance settings (or during macOS setup), the desktop picture defaults to a dark still image. To stop using a dark still image, click the pop-up menu, then choose Automatic or Light (Still).

* Desktop Pictures: These pictures remain static throughout the day.

* Note: If a thumbnail has a download icon , you must have an internet connection to download the image before you use it. To delete a downloaded picture, Control-click its thumbnail, then choose Remove Download.

* Colors: These swatches apply a solid-color background for your desktop. To choose a color not shown, click the Add button .

* Add Folder/Add Photo Album: Controls to choose your own photos from a folder or photo album. To add a folder, click Add Folder, then select a folder. To add a photo album, click Add Photo Album, then select Albums (all albums) or an individual album.

* If your photos aren’t shown, they might not be in the expected file format—JPEG, PICT, TIFF, PNG, or HEIC. Use Preview to open your photos and save them in one of the supported formats. See Save PDFs and images in Preview.

* If your photos are shown but look fuzzy, try using larger ones, such as 1024 x 768-pixel photos.

To modify a custom desktop picture or color, do any of the following:

* Cycle through multiple desktop pictures or colors: Click Auto-Rotate next to a custom folder or color to have desktop pictures or colors change periodically. Customize the timing or choose random cycling using the controls at the top of Wallpaper settings.

* Modify the desktop picture’s arrangement or dimensions: choose an option from the pop-up menu at the top of Wallpaper settings. Options include Fill Screen, Fit to Screen, Stretch to Fill Screen, Center, and more.

Customize the desktop picture on your Mac

If they steps are working for you, are your changes are retained, and you've followed these steps along with guidance from other threads, the logical next step will be to contact Apple Support.

Take care!