Select Background (or Template) for Slide doesn't seem to do anything?

From SLIDES > EDIT
Select Background (should it be

Leads to Pro Plus Templates

I Select one.
(it doesn't look like it's done anything until you click on the same Select button again for the Background )

You can't select a background from the other tabs? Motion Templates or Your Media Library?

I'm Confused. I'd like to use a slide with an image background, and not have to add it on every cue as a background.

Any update on this? Is it a "feature" or a bug that the only media that can be saved as a background for slides is the Pro Plus Templates?

You may be trying to edit the cue in the wrong place.
If you click on the cue in the list, then select "Edit Cue" from the panel, you will see, on the left, the list of background and foreground options, just as when you first created the cue. If you select the media option from the list, you will be taken to "Your Media Library". Select the required background, using the tick-box at the left hand end. (I now that sounds a bit odd, but it works. Selecting the background anywhere else does not).
The other suggestion to consider is to go to the settings and ensure that a default background has been selected. You may also find it useful to select the "inherit background when 'None' is selected" option.

@Paul That seems to have worked.

1. [+] to Add Cue Item
2. Select Foreground Slide > Select Slide
3. Select Background

Maybe the Background: Select Template in Slides should be renamed

I have managed to select a free pro template as the BG template for the slide, but it's inconsistent that you cant select your own media?