Hi ,
I think your problem may be, that sprite you’re displaying is not pixel perfect. To achieve you need to make sure, that each pixel in a graphic corresponds to a pixel of target monitor. If is not case engine has to fill inbetweens and these jittery artifacts appear. When using an ortographic camera you should be able to achieve a pixel perfect look when setting ortographic width to a multiple of screen resolution in a ratio that keeps pixels whole (1:1 2:1 4:1 etc).
You should also make sure, that your PPU (pixels per unit) is set uniformly. I use 1 pixel=1 unreal unit (you can set in sprite settings).
Lastly also make sure, that location of sprite fits into that pixel grid. (if you have 1 PPU, sprite locations should move in full Unreal Unit intervals and not sit at something arbitrary like (173.313385 cm/-204.879898 cm/3.869781 cm) Snapping everything to a grid size of 1 should help with that.
I hope I could be of help, here are some links that may help you further. Sadly there’s not a lot of information on how to do in Unreal on web.
https://www.reddit.com/r/unrealengine/comments/56ljmy/pixel_perfect_sprites_with_perspective_camera/