Adobe Illustrator: When moving a layer on top of another the colour of the top layer changes

[angelsneedwings]

When placing the elipses on top of the purple background layer the colour changes and all of the gradient colour disappears. I have tried playing around with the layers and the gradient of the individual elipses but nothing seems to be working. Can anyone help? 

[Michael Bullo]

Have you applied blending modes to any of your objects?

[angelsneedwings]

The blending mode is on screen for both objects. I have changed to normal for both and the effect is still the same sadly when the objects are placed on top of another.

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[tromboniator]

I'm not doubting your word that you changed both to normal, but have you checked each of them to be sure that the change actually happened?

Peter