Why is this Layer Hiding a layer ABOVE it?

[Agrajag]

I have an SVG that has several layers and one is a "Border" layer that sits BELOW a "Background" layer. The background layer has an image of a moon on it. The Background layer has an Opacity set to it of 80%. That doesn't seem to matter as even setting it to 100% doesn't impact this issue.

The Border layer is just a rectangle with rounded corners on it that fills the Page. The rectangle has a white fill. I generally keep this hidden (eye icon closed) as I only need to turn this on when printing an example of this card (for our continuing game prototype) for outsiders as it then takes on the shape of a card instead of a standard rectangle. Obviously I don't want to send that border (when on) to the printers.

When I turn on the Border layer it somehow covers the moon from the layer above and I have no idea why, though it has zero impact on any layer above that.

[Moini]

Check the Blend mode on the layers. Set it to 'normal'.

[Agrajag]

Check the Blend mode on the layers. Set it to 'normal'.

Not my issue. All layers are set to Normal.

[Moini]

Yes, you're right, the blend mode is on the moon image. I've only looked into your drawing with a text editor, and there is a blend filter in it.

[Agrajag]

Yes, you're right, the blend mode is on the moon image. I've only looked into your drawing with a text editor, and there is a blend filter in it.

I don't see that via the interface and am still unsure what to do about it.

[Moini]

Select the moon, do Filters > Remove filters.
Or in the objects dialog, change the blend mode to normal, after you have selected the moon on canvas.

You have probably been using the objects dialog, and accidentally changed the blend mode for the picture.
Blend modes are just filters.