Check the blend mode.

My guess:

The present mode has a black background, but editor canvas color is grey. Therefore, the gradient with blend mode appears different on various backgrounds.

You need to change the blend mode to normal or add background under the gradient.

Check the blend mode.

My guess:

The present mode has a black background, but editor canvas color is grey. Therefore, the gradient with blend mode appears different on various backgrounds.

You need to change the blend mode to normal or add background under the gradient.

 

Yup, that was problem. Thank you <3
I do not even remember when I edited blend mode.