Sprites Not Appearing Correctly in Launch

Hey everyone, new(ish) Unreal 4 developer here.

I’m working on a game featuring detailed 2D sprites, with a resolution of 1280 x 720. When I run the game in Play in Editor with an orthographic camera set to 1280 x 720 it looks just fine, but when I hit the ‘Launch’ button (or hit fullscreen when using Play in Editor) the resolution changes and the sprites become distorted and strange looking with a lot of jagged edges.

http://i.imgur.com/ECvYUdl.png

http://i.imgur.com/ECvYUdl.png - How it’s supposed to look, this is Play in Editor

http://i.imgur.com/H4Qb5Nk.png

http://i.imgur.com/H4Qb5Nk.png - When I hit Launch, and it’s also how it looks when I hit fullscreen.

I’ve worked with sprites of this size and a 1280x720 resolution before, when I made games in Ren’Py I had a similar setup and the sprites looked just fine when blown up to full screen, so it’s not a simple scaling issue. I’m guessing it’s not locking to the correct aspect ratio or there’s some sort of rendering issue in options, but I can’t find what I’m missing. Anyone got any ideas?

Anyone else know how to fix this?