Rendering of 3D sprite is different (worse) during runtime then in the editor

[gusty gust]

I'm making a card game and using 3D to give the game depth.
Here I am using two 3D sprites, one as the background and one as the card slot overlay. The problem is with the card slot overlay as the edges of the transparent texture are very rough during runtime but they're rendered properly in the editor.
The two pictures in this post are the same segment of the screen at the same screen size during runtime and during development in the editor.
How can I make it so the 3D sprite is rendered more "cleanly" during runtime as it is in the editor?

[gritty iris]

Would you mind posting your full Scene structure?

Do you have any WorldEnvironment nodes or Environments setup on the SubViewports/Cameras?

How is your scene lighting set up?

I'm having a hard time seeing the difference between your two images on my screen. Second image (runtime?) does look just a little brighter.

Which suggests to me it's getting different Lighting during Runtime.

Ah
1st image is Runtime
2nd image is Editor

I see the jaggies now.

What's your Project Display > Window > Size X Y ?

What is your Scaling set to?

[gusty gust]

Thank you for responding, thanks to you I got an idea and I fixed my issue. I changed the setting Display > Window > Stretch > Mode from viewport to canvas_items.

To actually answer your quests all lighting is turned off for the sprites.
The jiggle is a big problem since I want clean lines.
And yes I did use the setting Window Width/Height Override but changing that didnt do anything.
Changing the scaling of sprites didnt do anything and there was no window scailing.
Here's the scene tree: